8725 hacksaw cutting machine Diagrams, description, characteristics

Model 8725 Cutter Manufacturer Information

The manufacturer of the model 8725 hacksaw and cutting machine is the Krasnodar Experimental Plant named after. Kalinina .

Developed by Krasnodar Special Design Bureau of Automatic Lines.

The manufacturer of the model 8725 hacksaw and cutting machine is also PromStroyMash, Orenburg , founded in 2002.

On the Russian construction equipment market there are several domestic developers and manufacturers of hacksaw cutting machines and many foreign companies from China, Turkey, Bulgaria, etc.

Hacksaw cutting machines produced by machine tool enterprises of the USSR, Russia, Belarus:

• 8725 – PromStroyMash, Orenburg
• VSh-042, VSR-042 - Wistan, Vitebsk
• SN1 - Gomel plant of machine components
• MP6-1697 – Machine Tool Plant named after. Kirov, Minsk
• 8725 – Spectrum, Polevskaya, Sverdlovsk region
• 8725 – Krasnodar Experimental Plant named after. Kalinina (SIAL)
• 8715, SM-1 – Klin Machine Tool Plant – Klin Automatic Line Plant (KZAL)
• 8725A, 8725AM – StankoService, Aksai
• 872 – Troitsk Machine Tool Plant, Troitsk
• 8725-22 — Barnaul Machine Tool Plant
• 8B72K, N-1 - Kaunas Machine Tool Plant

Machine tools produced by the Krasnodar Experimental Plant named after. Kalinina

• 8B72
  - hacksaw-cutting machine Ø 250
• 872A
  - hacksaw-cutting machine Ø 250
• 872M
  - hacksaw-cutting machine Ø 250
• 8725
  — hacksaw-cutting machine Ø 250

Features and Benefits

Hacksaw machine

– a profitable purchase and long-term investment. This can be explained by the following advantages:

• Optimal cutting speed. Some devices are capable of operating at speeds of up to 32 m/min - an excellent indicator for cutting equipment. The speed is adjusted in steps. Fast cutting increases the efficiency of production processes.
• Reliable fixation. The material cut using a hacksaw machine is manually placed in a special vice. The risk of him falling and getting injured at work is completely eliminated.
• Safety of operation. Any cutting machine is equipped with reliable protection against spontaneous activation. Thanks to the cooling function, the processed material and working structural elements are not afraid of destruction and overload.
• Convenience and versatility of use. Cutting is performed in one of two ways: perpendicular to the axis of the workpiece or at an angle of 45°. To carry out cutting in the second way, the hacksaw machine is mounted on the saw frame.
• High power electric motor. This technical parameter allows the machine to withstand regular intensive loads to which it is inevitably exposed in production conditions.
• Extreme cutting precision. You can change the cutting mode settings yourself. With a high concentration of attention, it will be easy for you to maintain an accurate cut and cut out many parts of the same size.

General view of the cutting saw machine 8725

Photo of cutting saw machine 8725

Photo of cutting saw machine 8725

Photo of cutting saw machine 8725

Photo of cutting saw machine 8725

Photo of cutting saw machine 8725

How to install a hacksaw blade in a hacksaw machine

Before starting work, you need to insert the blade into the saw frame, which moves in one plane or another. To tension the fabric, you need to tighten the ram on the adjusting device. It is important to find the optimal tension force here. If the blade is installed correctly, i.e. without distortions, the cut during cutting will be smooth.

The feed movement of the working tool is usually carried out by swinging the frame around the trunnion. When working on a hacksaw machine, you must strictly follow safety rules.

Hacksaw cutting machines help to accurately and quickly cut metal workpieces. Manufacturers offer a variety of models with wide technological capabilities and many functions. Today there are many types of equipment, so choosing one is not difficult.

Kinematic diagram of the cutting hacksaw machine 8725

Kinematic diagram of the cutting hacksaw machine 8725

Bearing layout for cutting saw 8725

The machine is driven by an individual electric motor 5, N=3.0 kW, n=960 rpm. The movement of the motor is transmitted through a V-belt drive by pulley 8 to pulley 9, which rotates freely on axis I. The main shaft II can receive 2 revolutions thanks to two stages on the V-belt pulleys.

1. n1=55 rpm when transmitting motion from a smaller stage of the electric motor pulley to a larger stage of the pulley on axis I.
2. n2=114 rpm when transmitting motion from a larger stage of the electric motor pulley to a smaller stage of the pulley on axis I.

On shaft II, a crank disk 15 is mounted on a key from the pins of the crank 12. From it, by means of a connecting rod 4, the saw frame 2 receives a reciprocating motion with a number of double strokes corresponding to the number of revolutions of shaft II. Bearings 13 and 14 are installed on shaft II, transmitting movement to the pistons 17 and 18 of the hydraulic pump through rods with a hinge.

The pump pistons pump oil through the distribution valve 19 into the working cylinder 20, which is connected to sleeve 3 by means of a rod 23 and two hinges and can rotate it around the axis of sleeve III.

Thus, the raising and lowering of the saw frame 2, the feed during cutting, as well as the lifting of the blade during the reverse stroke is carried out by the hydraulic drive of the machine. Handle 25 serves to control the hydraulic drive. After finishing the cutting, in the lower position of the saw frame, the bar 28 hits the rail 16 and moves it.

Thus, through the gear 27, on the distribution valve 13, the distribution valve is installed in a position corresponding to the lifting of the saw frame, and the hacksaw blade is automatically raised to a height according to the pre-installed switch 22, which presses the limit switch 26.

The electric cooling pump operates when the toggle switch located on the electrical cabinet panel is turned on.

Operating procedure on the hacksaw machine 8725

To ensure proper operation of the machine when cutting various materials, you must be guided by the table:

The required number of double strokes of the saw frame is adjusted depending on the range of material being cut. The machine is delivered to the customer configured for 120 saw frame strokes. Changing the frequency of movement of the saw frame is carried out due to the V-belt transmission and the rotation of the pulley on the electric motor shaft by 180°.

When the pump is turned off, the saw frame may lower slightly.

The hacksaw blade is installed with the cutting direction away from the main drive.

It should be fairly tight. A loose blade will result in an incorrect cut. The tension force of the web should be 10-12 kN.

When installing the material and securing it, it is necessary to ensure that the workpiece lies on the supporting surface of the bed.

Brief description of the machine design

Machine drive

Motor 5 (see Fig. 2) is mounted on a frame 6, fixed to the frame 1 with a bracket 7. A V-belt drive pulley 8 is mounted on the motor shaft. A freely rotating second pulley 9 is mounted on axis 1, on the hub of which there is a helical gear 10 z=26, M=2.5, gear 11, z=145, M=2.5, which is mounted on a key on the main gear, engages with this gear. shaft II. The drive gears and pulleys are covered with a casing. The motor is started and stopped using the “Start” and “Stop” buttons.

When the hose is raised to its upper position, switch 22 presses the limit switch and automatically turns off the motor. Screw 33 serves to tension the V-belt drive belts.

bed

The bed (see Fig. 2) 1 has a box-shaped shape with a reinforcing rib inside. The lower part of the frame is a reservoir for coolant. The reservoir for the hydraulic drive oil is made integral with the frame. All components of the machine are mounted on the bed.

Rack

A cast iron stand 24 is mounted on the back side on top of the frame. The stand has sliding bearings for the main shaft II and for the axis III of the pumping arm.

The electrical cabinet is located on the rear side of the rack. On the inside of the stand, a sleeve support 31 is attached to a finger.

Sleeve

Sleeve 3, swinging on axis III, has dovetail-shaped guides on its lower surface along which the saw frame moves.

By means of a rod 23 and two hinges, the sleeve is connected to the piston rod of the working cylinder of the hydraulic drive, which controls the movement of the sleeve.

Saw frame

The saw frame 2 has guides in accordance with the sleeve guides and moves along them in a reciprocating motion from the crank disk 15, to which it is connected by a connecting rod 4.

Hacksaw blade 32 with one of its holes is put on the pin of a fixedly reinforced bar, and with the other hole on the pin of the movable bar and the special one is pressed. slats.

The tension of the hacksaw blade is carried out by a nut.

Clamping vice

To secure the material being cut, the machine is equipped with special clamps with flat grooved jaws.

Clamping is done using a screw and a stop.

Material stop

When cutting small workpieces of equal length, a stop 34 is used, which can be set in the desired position.

Location of controls

1. Input switch.
2. Control button “Start” of the machine drive
3. Handle for fixing the saw frame in the upper position
4. Handwheel for manual movement of the vice
5. Hydraulic drive control handle
6. The automatic shutdown of the machine is in the upper position of the saw frame.
7. Control button “Stop” of the machine drive.

Kinematic diagram of machine 8725

The movement from electric motor 1 is transmitted through a V-belt transmission and two stepped pulleys to drive shaft II, pulley 4, freely rotating on shaft II, is interlocked with gear 3. Through a gear pair 3 and 5, the movement is transmitted to shaft III at the other end of which a crank disk 10 is attached finger 9.

The saw frame receives reciprocating motion from the crank disk through connecting rod 13. Its movement frequency per minute is 120 (I stage) and 48 (II stage). To obtain the frequency of movement of the saw frame 62 (III stage) and 94 (IV stage), it is necessary to reinstall the drive pulley 2 by turning it 180°.

On shaft III between the two supports there are eccentric journals, from which the movement is transmitted by connecting rods to the pistons A and B of the hydraulic pump. The pistons pump oil into the distribution valve D, from where it flows to the working cylinder C. The piston of this cylinder is connected to the sleeve using articulated rods. Thus, the lifting and launching of the saw frame, as well as the working feed during cutting, is carried out from a hydraulic drive.

The hydraulic drive is controlled by handle E, which can be locked in position (Fig. 8.): I-“Inaction”, II- “Lowering”, III-“Lifting”, IV-“Slow cutting” and “Fast”.

Upon completion of cutting the workpiece in the lowest position of the saw frame, the bar K, attached to the saw frame, strikes the rail 6 and moves it. The rack, through the intermediate gear 7, transmits movement to gear 8, which is rigidly connected to the shaft of the distribution valve. In this case, the crane is installed in the saw frame lifting position. The saw frame rises until it presses the limit switch. This opens the electrical circuit, turning off the main drive motor.

The hydraulic drive of the hacksaw machine 8725 is controlled by handle E, which can be locked in the following positions: 1-“Inaction”, 11-“Lowering”, 111-“Lifting”, 1V-“slow cutting” and “Fast”. Upon completion of cutting the workpiece in the lowest position of the saw frame, the bar K, attached to the saw frame, strikes the rail 6 and moves it. The rack, through the intermediate gear 7, transmits movement to gear 8, which is rigidly connected to the shaft of the distribution valve. In this case, the crane is installed in the saw frame lifting position. The saw frame rises until it presses the limit switch. This opens the electrical circuit, turning off the main drive motor.

All hydraulic equipment of the machine is mounted in the pump housing. Piston pumps 1 and 2 suck oil from the oil reservoir through filters 6 and 7, check valves 9 and 10, located in the control valve body, and supply oil to the distribution valve through channels 15 and 16.

Bed.

The bed has a box-shaped shape; the main components of the machine are mounted on it (Fig. 2). The lower part of the frame contains a reservoir for cooling liquid. An electric cooling pump is also installed here. The oil reservoir for the hydraulic drive is cast together with the frame.

Drive unit.

The drive of the hacksaw machine 8725 consists of the following main parts: rack; sleeves and saw frame. The stand, mounted on the upper plane of the frame, on the right side, serves as a support for the sleeve and the drive shaft. The lower part of the sleeve has dovetail-type guides along which the saw frame moves. By means of a rod and two hinges, the sleeve is connected to the piston rod of the working cylinder of the hydraulic drive, which controls its movement. When the sleeve is raised to the upper position, the stop presses the limit switch and the electric motor automatically turns off. The saw frame carries out a reciprocating movement from the crank disk, with which it is connected to the connecting rod. The hacksaw blade is installed with one hole on the pin of a fixedly fixed bar, and the other - on the pin of the movable bar and is pressed with special bars. Before clamping the hacksaw blade, a bolt and nut are inserted into the grooves of the movable bars to tension the hacksaw blade. The speed range of 17, 22.34 and 43 m/min provides for cutting workpieces depending on the structure of the material being cut.

Fencing.

All rotating elements of the machine drive are protected by a casing mounted on the frame.

Vise.

To cut material of various profiles (square, rectangular, round), two strips, pos. 6, which allow you to cut workpieces of 25...250mm. The right jaw 1 is fixedly fixed on the machine bed. The workpieces are clamped by moving the left jaw 2, rotating the steering wheel 5 through the nut 4 and screw 3.

Cooling.

To cool the hacksaw blade, the machine has a cooling system consisting of a coolant reservoir, an electric pump, a hose and a special nozzle through which coolant is supplied to the cutting zone.

Combination vice (rotary) - optional.

Combination vice, designed for cutting material at an angle of 45°. The vice can clamp workpieces from 25 to 140 mm. The minimum length of the installed workpiece when cutting at an angle of 45° is 400 mm.

To cut material at an angle of up to 45°, it is necessary to: loosen 3 and 5, rotate jaw 2 to the required angle, then fix the angle of rotation of jaw 2 with screw 4 and secure it with nuts 3 and 5. The workpiece is clamped in a vice using a screw that moves the guide nut to to which jaw 1 is secured. Depending on the required size of the workpiece, jaw 2 is installed in one of three holes located on the frame.

Hydraulic equipment of machine 8725.

The hydraulic drive is designed to raise and lower the sleeve with the saw frame and is carried out by the working feed of the hacksaw blade during the cutting process. The feed amount is regulated by a manually operated hydraulic distribution valve. The maximum oil pressure in the system is set by a safety valve adjusted to a pressure within the range of 1.0...2.5 MPa/10...25kg (cm2).

Section of the hydraulic drive along the piston pump cylinder:

Section of the hydraulic drive along the hose lift cylinder:

Section of the hydraulic drive along the bushing of the control valve:

Hydraulic circuit diagram of machine 8725.

All hydraulic equipment of the machine is mounted in the pump housing. Piston pumps 1 and 2 suck oil from the oil reservoir through filters 6 and 7, check valves 9 and 10, located in the control valve body, and supply oil to the distribution valve through channels 15 and 16.

Regulation I – “Inaction”

When the valve is installed in this position, the piston pumps run idle, the oil flows through the grooves of the valve into the reservoir through channel 20. The machine sleeve remains motionless in any position. A saw frame with a hacksaw blade can only have a reciprocating motion along the sleeve.

Position II – “Lowering”

In this position, the piston pumps also operate at idle, but the oil from the rodless cavity of cylinder 3 through channel 17 and the grooves of the valve is drained into the reservoir through channel 20. The sleeve and saw frame smoothly lower down.

When the machine is operating, there are two positions in the working cycle: “Lifting” and “Cutting”.

Position III – “rise”

When installing the faucet handle in this position, the oil pumped by piston pumps through channels 15 and 16, the grooves of the faucet and to channel 17 is supplied to the lower cavity of cylinder 3. The hose and the saw frame with the hacksaw blade rise to the upper position. In the extreme position of the saw frame, the lower edge of the piston of cylinder 3 slightly opens a groove in the cylinder, through which excess oil is read through channel 18, tap grooves and channel 20.

Position IV – “Cutting”

In this situation, two stages of work should be considered:

• feeding of the cutting tool during the working stroke of the saw frame with the hacksaw blade;
• undercutting, that is, lifting the cutting tool above the workpiece being cut during the idle motion of the saw frame with the hacksaw blade.

Coordination of the reciprocating motion of the saw frame and the initial movement of the sleeve is ensured by the fact that the crank disk, which drives the saw frame, is mounted on a shaft with eccentric journals located at an angle of 125° to each other and transmitting the movement to pistons 1 and 2. The feed amount is regulated by turning handles of a variable-section valve connecting the cavities of the piston 1 and the rod cavity of the cylinder 3 with drainage through channel 20.

Depending on the position of the handle, the amount of oil entering the rod cavity of cylinder 3 is adjusted. Slow cutting is carried out with the throttle open, which corresponds to the upper position of the handle. Most of the oil is drained through the throttle slot, and the rest enters through channel 18 into the rod cavity of cylinder 3. Fast cutting is carried out with the valve handle turned and the throttle closed. In this case, the throttle is completely closed and all the oil is pumped into the rod cavity of cylinder 3,

Fast cutting is carried out with the valve handle turned and the throttle closed. In this case, the throttle is completely closed and all the oil is pumped into the rod cavity of cylinder 3, creating maximum feed to the hacksaw blade. Excess oil is drained through safety valve 4.

The lifting of the cutting tool above the workpiece at idle speed is carried out when piston 2 moves downwards. Before the side hole in the piston 2 cylinder is closed, the oil is drained through it through channels 19 and 20 into the reservoir. After blocking this hole with the piston, oil flows through channels 16 and 17 into the rodless cavity of cylinder 3 and the saw frame with the hacksaw blade is raised.

Adjustment of the amount of undercut is carried out by changing the length of the rod between the crankshaft and the piston due to the threaded connection of the hinge bolt screwed into the bearing housing

Installation and operation instructions.

Mineral hydraulic oil is poured into the hydraulic system reservoir. The working fluid is oil “Industrial I-20A” GOST 20799-88. You can use oil “Industrial I-30A” GOST 20799-88 or “Turbine 122” GOST 32-74.

Before filling the oil, the tank must be thoroughly cleaned and rinsed with kerosene. The oil is poured clean, pre-filtered twice with an absolute particle size of no more than 40 microns, with a viscosity in the range of 20∙10-6...35∙10-6 m2/s at a temperature of 50°C to the oil indicator level.

The first oil change must be made one month after the start of operation, and also every six months. Before filling with fresh oil, the tank should be thoroughly cleaned and rinsed with kerosene.

Initial start-up of the hydraulic system.

The initial start-up of the hydraulic system is carried out as follows. Check the presence of oil in the reservoir using the oil level indicator. Set the hydraulic control valve handle to the “Lift” position.

After making sure that the saw frame rises, it is necessary to set the control valve to the “Cutting” position. In this position, the machine should operate until air is removed from the hydraulic system through the nozzle shown in Fig. 9. The hydraulic system should be flushed with working fluid for at least 8 hours, and the hydraulic drive valve should be set to the neutral position.

After this, the machine can be used.

Adjustment of the amount of undercut is carried out by changing the length of the rod between the crankshaft and the piston due to the threaded connection of the hinge bolt screwed into the bearing housing.

Hydraulic drive of cutting saw machine 8725

Hydraulic drive of cutting saw machine 8725

Hydraulic drive of cutting saw machine 8725

Using a hydraulic drive (Fig. 3), the hacksaw blade is raised and lowered.

The canvas can be installed at a constant height.

When cutting, at the beginning of the working stroke, the pressure of the blade on the material being cut is minimal, then it gradually increases and drops shortly before the end of the working stroke. During the reverse stroke of the saw frame, the hacksaw blade rises and does not come into contact with the material being cut.

Depending on the type of material, the feed amount is smoothly adjusted by throttling the oil.

The maximum oil pressure is determined by the strength of the hacksaw blades and is set by a safety valve.

All control of the hydraulic drive is carried out by a crane 19 with a handle 25. The handle 25 with a pointer 60 moves on a scale 61, equipped with the inscriptions: “Lifting”, “Lowering”, “Inaction”, “Slow action”, “Faster”, which sets the operating mode of the hacksaw canvases ranging from minimum to maximum.

The hydraulic drive housing 62 is mounted on the glass 1 and enters the oil reservoir 34. Oil and the reservoir are filled through hole 63, for which it is necessary to unscrew the plug 75. The oil indicator 85 has a line on the glass corresponding to the normal oil level. The oil is released through a hole in the glass, closed with plug 59.

In the hydraulic pump body, 2 inclined cylinders 66 and 67 are bored out with bimetallic bushings pressed into them. Pistons 17 and 18 of cylinders 66 and 67 receive movement through rods 72 and 73 from bearings 13 and 14 sitting on shaft II. Pistons 17 and 18 suck oil from reservoir 34 through filter 68 and pump it through the channels of valve sleeve 74 and valve plug 19 into working cylinder 20.

The piston rod 78 is pivotally connected to the rod 23 with the sleeve 3 and controls its movement. The tap plug 19 is turned by handle 25. When cutting is completed, the tap plug is automatically set to the “Lifting” position and the hacksaw blade rises. The seal in the tap is achieved by tightening the nut 75.

To set the safety valve 58 to the desired pressure, the degree of compression of the spring 79 is adjusted by screw 80.

Channel 81 serves to supply oil to the control pressure gauge and must be closed with plug 82 when the machine is operating. Safety valve 58 must be adjusted to a pressure of at least 25 atmospheres.

When adjusting the valve, a control pressure gauge is screwed in instead of plug 82.

Description of the hydraulic drive circuit

In Fig. 4, 5, 6, 7, 8 show diagrams of the hydraulic drive of the machine for the main positions of the crane.

1st position “Inaction” (drawing No. 3). In this position, the sleeve connected to the piston 78 of the working cylinder 20 is motionless.

Oil from the upper cavity of cylinder 20 exits through channels 103, 91, 92, 109, and 93 into the reservoir and through channels 103, 90, 89 and 88 and cylinder 67, since at this moment the piston 17 moves up and sucks in oil.

2nd part of the reverse idle movement of the saw frame.

In the 2nd part of the return stroke, piston 18 and then piston 17 change direction of movement and piston 78 is lowered.

1st part of the working stroke of the saw frame.

Immediately after the start of the working stroke, the hacksaw blade comes into contact with the material being cut and with further movement of the frame, the blade receives a feed in the following way: piston 17, continuing to move downward, pumps oil into the upper cavity of the cylinder 20. Pressure from piston 78 in the upper cavity is created by throttling the excess volume of oil discharged into the reservoir through channels 91, 92, throttling channel 109 and hole 93.

Oil from the lower cavity of the cylinder 20 has an outlet into the reservoir through channels 83, 84, 97, 96 and 95, 108, 110 and 111, since the piston 18 in this part of the stroke is located above the hole 108 and cylinder 66.

2nd part of the working stroke of the saw frame.

In the second part of the power stroke, piston 18 changes direction of movement and begins to pump oil, since piston 18 is located above channel 108, the pumped oil is discharged through channels 108, 110 and 111 into the reservoir.

Shortly before the end of the working stroke, piston 17 also changes its direction and begins to suck. Immediately after this, piston 18 closes channel 103 and begins to pump oil through channels 95, 96, 97, 84 and 83 into the lower cavity of cylinder 20. Piston 78 moves upward. The hacksaw blade is raised above the material being cut.

5th position – “Fast action”

The pressure from above on the piston 78 in the 4th position is insignificant, since the pressure difference in the throttling channel 109 is insignificant. When the handle of the valve plug is rotated clockwise from the 4th position, the cross-section of the throttling channel 109 gradually narrows and the pressure from above on the piston gradually increases. In the 5th position, obtained by turning the handle 135° clockwise from the 4th position, the cross-section of the throttling channel is reduced to zero. The excess oil volume now flows through the safety valve 58 into the reservoir. The maximum pressure to which safety valve 58 is adjusted should not exceed 25 atm. and is installed according to control pressure gauge 112.

Diagram of the hydraulic drive of the hacksaw machine 8725. 1st position “Inaction”

Diagram of the hydraulic drive of the hacksaw machine 8725. 2nd position “Lowering”

Diagram of the hydraulic drive of the hacksaw machine 8725. 3rd position “Lifting”

Diagram of the hydraulic drive of the hacksaw machine 8725. 4th position “Lowering slowly”

Diagram of the hydraulic drive of the hacksaw machine 8725. 5th position “Action quickly”

Installation procedure for hacksaw machine 8725

The machine is delivered to the consumer on shipping bars, packed in T-grade plastic film or in partial packaging; at the client’s request, the machine can be packed in a wooden box.

When unpacking, care must be taken not to damage the machine with the unpacking tool.

To transport the unpacked machine, it is necessary to use cables with a diameter of at least 10 mm, pass them through the window in the frame.

When gripping the machine with a cable, care must be taken not to damage the outer finish of the machine, for which purpose wooden spacers must be placed under the cable in appropriate places.

When transporting to the installation site, it is necessary to avoid strong tilting of the machine, and when lowering the machine to the foundation, it should not be subjected to strong shocks.

Before installation, the machine must be thoroughly cleaned of the anti-corrosion coatings applied to the machined surfaces before packaging the machine and, to avoid corrosion, coated with a layer of industrial oil I-20A TU 0253-043-48120848-2005.

Cleaning is first done with a wooden spatula, and the remaining lubricant from the outer surfaces is removed with napkins moistened with gasoline B-70 TU 38. 101913-82.

The machine is installed on a foundation or concrete pad. The depth of the foundation depends on the soil, but must be at least 170 mm. The machine is attached to the foundation with four foundation bolts with a diameter of 20 mm. Foundation bolts are not supplied from the factory.

The machine is installed on the foundation and aligned in both planes using a level installed on the frame. The deviation should not exceed 0.1/300 mm in both planes

Dimensions for reference

The foundation depth H is determined depending on the soil.

Maintenance and care of the machine

The machine is sent to the factory adjusted and tested on the fly.

Before putting the machine into operation, it is necessary to set the saw frame to the required number of double strokes. When cutting hard metals, the hacksaw is given 55 strokes/min. When cutting soft – 114 stroke/min. About 10 liters of Industrial I30 oil are poured into the machine hydraulic drive oil reservoir. The oil level is monitored using the oil indicator.

It is necessary to check the lubrication of the machine, replenish the oilers with oil and add oil to the drive gears. The coolant is poured into the lower part of the frame, which serves as a reservoir. The amount of coolant is about 20 liters. A good coolant is 6-10%; solution of "Emulsol" in water. The vice is installed on the machine in such a way that the axis of the workpiece being cut comes in the middle of the saw frame stroke. When installing the material and securing it with a vice, you must ensure that the workpiece lies horizontally and at an angle to the hacksaw blade. Particular attention should be paid to the condition of the hacksaw blade. The canvas must be stretched, its teeth must be sharp.

A loose blade will make an incorrect cut, and a blade with dull or broken teeth will work unproductively and give a poor cut with an uneven surface, and may break if the metal is tough.

Before starting to work on the machine, it is necessary to run the machine idle for a short time in order to remove the air in the cylinders and channels of the hydraulic drive. Air from the plug 82 is released when it is not completely unscrewed when starting the machine, since the machine sleeve is in the lower position, the handle 25 of the hydraulic drive valve is placed in the “Lift” position and then the motor is turned on by pressing the “Start” button. After the air has been removed and the hydraulic drive shows normal operation in all positions, the crane handles can be used to operate the machine.

When starting the machine, place the crane handle in the “Lowering” position and turn on the motor. After the blade is lowered to the material being cut, the crane handle is moved to the “Slow Action” position for preliminary cutting. Then use the same handle to set the desired feed.

Further operation of the machine occurs automatically. At the end of the cutting, the saw frame bar, hitting the rail 16, moves the handle 25 to the “Lifting” position. The saw frame rises and the machine stops. The position of rack 16 relative to the gear sitting on the valve plug is set by the factory and cannot be adjusted. The position of switch 25 relative to the sleeve is set with two screws. For normal operation of the machine, it is necessary to use clean mineral oil, free of acids and other impurities, for the hydraulic drive and lubrication. The coolant should not be contaminated or clogged with small metal particles and should be filtered or replaced periodically. The electrical part should be free of dust, dirt and especially oil.

The ball bearings of the motor must be lubricated with an acid- and alkali-free grease, which is changed periodically. Bearings must be thoroughly washed with gasoline before filling them with lubricant. All wire connections must be strong and reliable. Loose contacts must be tightened, and their surface must be thoroughly cleaned of the layer of oxides.

The temperature conditions of the workshop in which the machine is to operate must be from +15° C and above (according to UHL4).

Adjustment of wear parts

• 1. Wear of the saw frame guides is compensated by moving the movable wedge of the saw frame by tightening the screw.
• 2. Wear of the valve plug 19 and the valve bushing is compensated by tightening the nut 75 until the desired seal is obtained.

Malfunctions in the operation of the machine and methods for eliminating them

When cutting, the machine shows low productivity:

• check the seal in the tap and eliminate the leak;
• check the seal in the plugs that seal the channels in the hydraulic pump housing;
• adjust the safety valve.

Preparation for the initial start-up of the hacksaw machine 8725

Ground the machine by connecting to the general workshop grounding system.

Connect the machine to the electrical network, checking the consistency of the network voltage and the electrical equipment of the machine.

Pour about 10 liters of “Industrial I-20A” oil into the hydraulic reservoir according to GOST 20799-88.

Pour 20 liters into the tank (lower part of the frame). Coolant. A good coolant is a 6-10% solution of Emulsol in water according to GOST 6243-75-75 or Ukrinol 1 TU 38-101-197-76.

After familiarizing yourself with the meaning of the control handle, you should check by hand the operation of all machine mechanisms.

Follow the instructions given in the “Hydraulic system”, “Lubricating system” and “Electrical equipment” sections related to start-up.

After connecting the machine to the network, test the electric motor without turning on the working parts of the machine, paying attention to the correspondence of the rotation of the electric motor pulley with the arrow marked on the casing.

To familiarize yourself with the machine in detail, it is recommended to run it at idle speed and understand the purpose and operation of the controls.

After making sure that all machine mechanisms are working properly, you can begin setting up the machine for operation.

Cutting saw tools 8725

Dimensions of hacksaw blades

Cutting the material on hacksaw machines is done with hacksaw blades, which are made of steel P9, P18 or ШХ 15.

Hacksaw blades are selected according to the length and pitch of the teeth, depending on the size of the workpiece being cut and the material. The main dimensions of hacksaw blades are given in table. 69.

The pitch of the teeth of hacksaw blades is selected depending on the thickness of the workpiece being cut and its material. Hacksaws with fine teeth are used for cutting thin workpieces and hard materials, hacksaws with large teeth are used for workpieces with large cross-sections and soft materials.

Thus, when cutting steel σвр = 40-60 kg/mm2 with machine hacksaws, hacksaws with a tooth pitch of 3..4 mm are recommended, steel σвр = 60 kg/mm2 - with a pitch of 2.5 mm.

Tooth shape of hacksaw blades

Typically, the tooth shape of hacksaw blades is triangular (Fig. 27).

For machine-made hacksaw blades, the rake angle is γ = 0–5°, the rear angle is α = 35–40°, the sharpening angle is β = 50–55°, and the radius of the depressions is 0.5–1.5 mm. The All-Union Scientific Research Instrumental Institute recommends a symmetrical tooth with a rake angle γ = - 30° and a sharpening angle β = 60°

These hacksaw blades have less tooth wear, increased productivity and, when dull, can be additionally used by installing the other end.

To reduce lateral friction, the teeth of the hacksaw blades have a set of 0.6-0.8 mm. The difference in the height of the tops of adjacent blade teeth should not exceed 0.1 mm for blades with a tooth pitch of 1 mm and 0.15 mm for blades with a tooth pitch of more than 1 mm.

The performance of hacksaw machines depends on the pressure on the blade, which is recommended to be selected depending on the thickness of the blade. Thus, with a hacksaw blade thickness of 0.8, 1 and 2 mm, the pressure is 5, 10 and 30 kg, respectively.

During operation, the blade must be tightly stretched on the frame; after several strokes of the saw, it is necessary to tighten the blade a second time.

General view of the 8725 machine with designation of components

Technical characteristics of mechanical hacksaw 8725

Bibliography:

1. Hacksaw machine 8725. Operating manual 8725.00.001 RE, Plant named after. M.I. Kalinina, Krasnodar, 1975
2. Veselovsky S.I. Cutting materials, 1973
3. Drozdov F., Lebedevich V., Rubezhin V. Reference manual on cutting machines, 1967

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Operating instructions for hacksaw machine 8725

• Machine 8725 is serviced by a third-class worker. One worker operates three machines.
• When cutting workpieces up to 350 mm long, it is recommended to install technological containers manufactured by the customer. When cutting workpieces longer than 350 mm, it is necessary to install a receiving tray (supporting device) to prevent the workpieces from falling to the floor to avoid injury.

• During the operation of the machine, there is a need to regulate individual parts of the machine in order to restore it from normal operation. If the main drive belts become loose due to their stretching, loosen the bolt on the grooved bar, tighten the belts, then tighten the bolt again.
• Wear the saw frame guides by tightening them with round nuts. During idling, the size of the saw frame above the material being cut, the so-called “undercut,” is regulated by changing the distance between the crankshaft and the piston due to the threaded connection of the hinge bolt 1 and bearing 2 (see Fig. Section of the hydraulic drive along the piston pump cylinder). To adjust, it is necessary to increase the distance between the piston and the crankshaft, and to decrease it, to reduce it. After final adjustment, tighten nut 3 on hinge bolt 1 again. The undercut size should be at least 1.5-2.5 mm.
• Depending on the type of material being cut (see table above) and the strength of the hacksaw blade, the pressure in the hydraulic system is regulated by a safety valve. First, plug 1 is unscrewed (see Fig. 9), then to increase the pressure in the system, it is necessary to tighten screw 2, compressing the spring 3 of the safety valve, and to reduce the pressure in the hydraulic system, it is necessary to loosen spring 3, and then tighten plug 1 again.
• The wear of the valve plug 1 and the valve bushing 2 (see Fig. Section of the hydraulic drive along the control valve bushing) is completed by tightening the nut 3 to the desired seal.
• Elimination of noise in gearing 3 (see Fig. Section of the hydraulic drive along the hose lift cylinder) is done by rotating the eccentric axis of shaft 11, having previously unscrewed the two nuts located inside the frame.

Model features

• Climatic modification according to GOST 15150-69-UHL4.
• The vice is equipped with a special bracket for securing workpieces.
• The saw frame is driven by a separate electric motor through a crank mechanism. The wire pulleys are made of two stages so that the number of double strokes can be varied.
• Raising and lowering the saw frame, feeding the hacksaw blade during cutting, and lifting the saw frame during the reverse stroke are carried out using a hydraulic drive. The saw frame returns to the top position at the end of cutting automatically.
• Coolant is supplied to the hacksaw blade during the cutting process.
• The accuracy class of the metal cutting machine is N according to GOST 8-82E.

Model features

• Climatic modification according to GOST 15150-69-UHL4.
• The vice is equipped with a special bracket for securing workpieces.
• The saw frame is driven by a separate electric motor through a crank mechanism. The wire pulleys are made of two stages so that the number of double strokes can be varied.
• Raising and lowering the saw frame, feeding the hacksaw blade during cutting, and lifting the saw frame during the reverse stroke are carried out using a hydraulic drive. The saw frame returns to the top position at the end of cutting automatically.
• Coolant is supplied to the hacksaw blade during the cutting process.
• Accuracy class