Tool clamp for turning oil cylinder cover lifting lug

Abstract

The invention provides a tool clamp for turning a lifting lug of an oil cylinder cover. The tool clamp mainly comprises a connecting seat, a base, a balancing weight, a central positioning shaft, a pressing plate, a V-shaped pressing block, a rear connecting rod, a front connecting rod and a swing bolt. When an oil cylinder cover is turned, the bottom of a workpiece is fixed to a center positioning shaft, the top end of a circular ring of a lifting lug makes contact with a V-shaped pressing block, the V-shaped pressing block is connected to a pressing plate through a cylindrical pin, the two sides of the pressing plate are each provided with a supporting arm, and the supporting arms are connected with a front connecting rod and a rear connecting rod through grooves respectively. The V-shaped pressing block can make contact with the top end of a lifting lug of the oil cylinder cover workpiece, and the oil cylinder cover workpiece is restrained on the tool clamp by locking the swing bolt. According to the tool clamp, automatic alignment of a workpiece can be achieved, so that positioning errors are reduced, the universality of the clamp can be guaranteed through the design of the center positioning shaft, the tool clamp is suitable for machining of parts of the same type and different dimensions, and therefore the clamp cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of machining, and particularly relates to a fixture for turning the lifting lugs of an oil cylinder cover. Background Art

[0002] As a key actuator in a hydraulic system, the oil cylinder is widely used in various construction machinery fields. The oil cylinder cover is an important part connecting the oil cylinder body and other components, and its processing quality directly affects the working reliability of the oil cylinder. The oil cylinder cover usually has a double - cylindrical structure and presents a lifting lug state. The lifting lug part is generally approximately annular, with holes, sealing grooves and oil passages for connecting other components. There are strict requirements for the dimensional accuracy, position accuracy and surface roughness of the holes and grooves in the lifting lug part. During the processing of the lifting lug part of the oil cylinder cover, the design of the fixture is crucial. It not only needs to ensure the positioning accuracy of the oil cylinder cover during processing, but also withstand the cutting force and other external forces during processing. Traditional fixtures have problems such as insufficient positioning accuracy, low efficiency and poor versatility. Therefore, it is crucial to design a precise and efficient fixture for machining the lifting lug part of the oil cylinder cover. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] The present invention provides a fixture for turning the lifting lugs of an oil cylinder cover to solve the technical problems of low positioning accuracy, poor clamping efficiency and insufficient versatility during the processing of the oil cylinder cover.

[0005] (2) Technical Solutions

[0006] To solve the above - mentioned technical problems, the present invention provides a fixture for turning the lifting lugs of an oil cylinder cover, which includes a connecting seat, a base, a counterweight, a center positioning shaft, a pressing plate, a V - shaped pressing block, a rear connecting rod, a front connecting rod and a swivel bolt; among them,

[0007] The left end of the connecting seat has a taper - shank structure for mating and connecting with the inner taper of the lathe spindle. An internal threaded hole is machined at the center of the left end of the taper - shank for installing the spindle drawbar; the right end of the connecting seat is a rectangular - cuboid structure connected to the taper - shank structure; threaded holes for installing the counterweight are machined on the upper plane of the rectangular - cuboid, and threaded holes for connecting the base are machined on the lower plane of the rectangular - cuboid;

[0008] The base is a rectangular - cuboid structure. A through counterbore is machined at the left end. The hexagon socket head cap screw passes through the counterbore of the base and is screwed into the threaded hole on the lower plane of the right - end rectangular - cuboid of the connecting seat to fixedly connect the connecting seat and the base; a center positioning hole is machined at the middle position of the right end of the base for installing the center positioning shaft, and threaded holes for connecting the rear connecting rod and the front connecting rod are respectively machined on both sides of the center positioning hole;

[0009] The counterweight is of a cuboid structure, with countersunk holes penetrating the upper and lower planes. The socket head cap screws are sequentially inserted into the countersunk holes and screwed into the threaded holes on the upper plane of the right-end cuboid of the connecting seat, fixedly connecting the counterweight to the connecting seat.

[0010] The center positioning shaft is of a stepped shaft structure. The lower end of the stepped shaft is connected to the center positioning hole of the base through interference fit, and the upper end of the stepped shaft forms a clearance fit with the inner hole at the lower end of the cylinder head cover workpiece.

[0011] The pressing plate is of a cuboid structure with support arms at the front and rear ends. The rear support arm of the pressing plate is processed with a rear groove for connecting to the rear connecting rod, and a connecting hole is processed on the side of the rear groove. After the cylindrical pin is inserted into the connecting hole, it is connected to the upper connecting hole of the rear connecting rod; the front support arm of the pressing plate is processed with a front groove for the knuckle bolt to pass through; the bottom of the pressing plate is of an arc groove structure, and a connecting hole is processed on the side of the arc groove. The upper arc of the V-shaped pressing block is inserted into the bottom arc groove of the pressing plate, and the cylindrical pin is inserted into the connecting hole on the side of the arc groove and the connecting hole on the side of the V-shaped pressing block to connect the V-shaped pressing block to the pressing plate. The depth and width of the arc groove are greater than the upper arc of the V-shaped pressing block.

[0012] The upper end of the V-shaped pressing block is of an arc structure, and a connecting hole for inserting a cylindrical pin is processed on the side of the arc structure; the lower end of the V-shaped pressing block is a V-shaped groove for contacting the cover ring part of the cylinder head cover workpiece; the V-shaped pressing block and the pressing plate are connected in a floating manner. When the pressing plate is pressed and stressed, the V-shaped pressing block can automatically fine-tune the angle to ensure uniform force on the contact surface between the V-shaped pressing block and the cylinder head cover workpiece, and restrict the cylinder head cover workpiece to rotate along the center positioning shaft.

[0013] External threads are processed at the lower ends of the rear connecting rod and the front connecting rod, and they are symmetrically installed on the two connecting rod installation threaded holes of the base; the upper end of the rear connecting rod is of a symmetric stepped structure, and a connecting hole is processed on the side of the stepped protrusion. The rear connecting rod is connected to the rear groove of the pressing plate through a cylindrical pin; the upper end of the front connecting rod is of a groove structure, and a connecting hole is processed on the side. It is connected to the lower end of the knuckle bolt through a cylindrical pin, and the upper end of the knuckle bolt passes through the front groove of the pressing plate and is connected to the locking nut. The knuckle bolt can be perpendicular to the base under the limitation of the front groove.

[0014] Further, the left end of the connecting seat is of a Morse No. 6 taper shank structure.

[0015] Further, for the machining accuracy of the dimension from the bottom surface of the cylinder head cover workpiece to the center of the lifting lug of 60 ± 0.05 mm, the distance from the lower plane of the right-end cuboid of the connecting seat to the center of the taper shank is 60 ± 0.015 mm.

[0016] Further, positioning holes for inserting positioning pins are processed on the lower plane of the right-end cuboid of the connecting seat and the left end of the base, and positioning pins are respectively inserted into the positioning holes.

[0017] Furthermore, the inner hole clearance between the upper end of the stepped shaft and the lower end of the oil cylinder cover workpiece is controlled within 0.025 mm.

[0018] Furthermore, the connecting seat, base, pressing plate, rear connecting rod, front connecting rod, knuckle bolt and V-shaped pressing block are made of 40Cr bar stock or sheet metal, and the quenched and tempered hardness is HRC38 - 42.

[0019] Furthermore, the counterweight and the center positioning shaft are made of 45# steel, and the quenched and tempered hardness is HRC28 - 32.

[0020] Furthermore, the cylindrical pin is selected as a hardened cylindrical pin standard part of GB119.

[0021] Furthermore, the locking nut is selected as a 9-level high-strength pressing plate nut standard part.

[0022] Furthermore, after putting washers on the hexagon socket head cap screws, they are sequentially inserted into the counterbore holes of the counterweight and screwed into the threaded holes on the upper plane of the right-end cuboid of the connecting seat; the upper end of the knuckle bolt passes through the front groove of the pressing plate and is connected to the washer and the locking nut; the washer is made of 45# steel, and the quenched and tempered hardness is HRC28 - 32.

[0023] (III) Beneficial Effects

[0024] The present invention provides a fixture for turning the lifting lugs of an oil cylinder cover, mainly including a connecting seat, a base, a counterweight, a center positioning shaft, a pressing plate, a V-shaped pressing block, a rear connecting rod, a front connecting rod and a knuckle bolt. When turning the oil cylinder cover, the bottom of the workpiece is fixed on the center positioning shaft, the top of the ring of the lifting lug part contacts the V-shaped pressing block, the V-shaped pressing block is connected to the pressing plate through a cylindrical pin, there is a support arm on each side of the pressing plate, which are respectively connected to the front and rear connecting rods through grooves. By flipping the pressing plate, the V-shaped pressing block can be made to contact the top of the lifting lug of the oil cylinder cover workpiece, and by tightening the knuckle bolt, the oil cylinder cover workpiece can be constrained on the fixture. The fixture of the present invention can realize the automatic alignment of the workpiece, thereby reducing the positioning error, and the design of the center positioning shaft can ensure the versatility of the fixture, which is applicable to the processing of parts of the same type with different sizes and specifications, thereby reducing the fixture cost. Description of the Drawings

[0025] Figure 1 It is the overall structure diagram of the working state of the fixture of the present invention;

[0026] Figure 2 It is the overall structure diagram of the state of the workpiece to be clamped by the fixture of the present invention;

[0027] Figure 3 It is the exploded structure diagram of the working state of the fixture of the present invention. Specific Embodiments

[0028] To make the objectives, content, and advantages of the present invention clearer, the following further describes in detail the specific implementation manners of the present invention in conjunction with the accompanying drawings and embodiments.

[0029] This embodiment provides a fixture for turning the lifting lugs of an oil cylinder cover, and its structure is as Figures 1 to 3 shown, mainly including a connecting seat 4, a base 16, a 6mm positioning pin 5, a counterweight 3, a center positioning shaft 14, a pressing plate 8, a V-shaped pressing block 11, a rear connecting rod 13, a front connecting rod 15, and a swivel bolt 12.

[0030] The left end of the connecting seat 4 is a Morse No. 6 taper shank structure for mating and connecting with the inner cone of the lathe spindle. The center part of the left end of the taper shank is machined with an M16 internal threaded hole for installing the spindle drawbar to ensure the safety of the connection. The right end of the connecting seat 4 is a cuboid structure connected to the taper shank structure. To ensure the machining accuracy of the dimension of 60±0.05mm from the bottom surface of the oil cylinder cover workpiece 0 to the center of the lifting lug, the distance from the lower plane of the cuboid to the center of the taper shank is designed to be 60±0.015mm to improve the positioning accuracy of the fixture. Two threaded holes for installing the counterweight 3 are machined on the upper plane of the cuboid, and three threaded holes for connecting the base 16 and two positioning holes for inserting the 6mm positioning pin 5 are machined on the lower plane of the cuboid.

[0031] The base 16 is a cuboid structure, with three through counterbored holes and two positioning holes machined at the left end. The 6mm positioning pin 5 is inserted into each of the two positioning holes. Three internal hexagonal bolts 1 are passed through the three counterbored holes of the base 16 after putting on single washers 2 and screwed into the three threaded holes on the lower plane of the right-end cuboid of the connecting seat 4 to fixedly connect the connecting seat 4 and the base 16. The two 6mm positioning pins 5 are inserted into the two positioning holes on the lower plane of the right-end cuboid of the connecting seat 4 to prevent relative displacement between the base 16 and the connecting seat 4 during machining under force, resulting in errors in the geometric tolerances of the workpiece. A center positioning hole is machined at the middle position of the right end of the base 16 for installing the center positioning shaft 14, and connecting rod installation threaded holes for connecting the rear connecting rod 13 and the front connecting rod 15 are machined on both sides of the center positioning hole.

[0032] The counterweight 3 is a cuboid structure, with two through counterbored holes machined on the upper and lower planes. Two internal hexagonal bolts 1 are passed through the two counterbored holes after putting on washers 2 and screwed into the two threaded holes on the upper plane of the right-end cuboid of the connecting seat 4 to fixedly connect the counterweight 3 and the connecting seat 4. The counterweight 3 is used to balance the center of gravity of the entire fixture during high-speed rotation, ensuring the machining accuracy and safety of the product.

[0033] The central positioning shaft 14 has a stepped shaft structure. The lower end of the stepped shaft is connected to the central positioning hole of the base 16 by interference fit. The upper end of the stepped shaft forms a clearance fit with the inner hole at the lower end of the cylinder head workpiece 0, and the clearance is controlled within 0.025 mm. By replacing the central positioning shaft 14 with different outer diameters, the clamping and positioning of the cylinder head workpieces 0 with different diameters can be achieved.

[0034] The pressure plate 8 has a cuboid structure with support arms at both the front and rear ends, and is used to transmit the downward pressure generated by tightening the lock nut 6. Among them, the rear support arm of the pressure plate 8 is machined with a rear groove for connecting with the rear connecting rod 13. A connecting hole is machined on the side of the rear groove. After the 10 mm cylindrical pin 9 is inserted into the connecting hole, it is connected to the upper connecting hole of the rear connecting rod 13. The rear groove can prevent interference with the rear connecting rod 13 when the pressure plate 8 flips. The front support arm of the pressure plate 8 is machined with a front groove for the articulated bolt 12 to pass through. The bottom of the pressure plate 8 has an arc groove structure. A connecting hole is machined on the side of the arc groove. The upper arc of the V-shaped pressing block 11 is inserted into the bottom arc groove of the pressure plate 8. The 8 mm cylindrical pin 10 is inserted into the connecting hole on the side of the arc groove and the connecting hole on the side of the V-shaped pressing block 11 to connect the V-shaped pressing block 11 with the pressure plate 8. The depth and width of the arc groove are larger than the upper arc of the V-shaped pressing block 11, so that the V-shaped pressing block 11 can swing left and right around the 8 mm cylindrical pin 10 without interference.

[0035] The upper end of the V-shaped pressing block 11 has an arc structure, and a connecting hole for inserting the 8 mm cylindrical pin 10 is machined on the side of the arc structure. The lower end of the V-shaped pressing block 11 is a 90° V-shaped groove, which is used to contact the ring part of the cylinder head of the cylinder head workpiece 0. Under the condition of non-interference during processing, the V-shaped groove is as close as possible to the width of the cylinder head ring. Since the cylinder head workpiece 0 is made of casting material and the outer surface of the lifting lug part is irregular, the V-shaped pressing block 11 and the pressure plate 8 are connected in a floating manner. When the pressure plate 8 is pressed downward and stressed, the V-shaped pressing block 11 can automatically adjust the angle to ensure that the contact surface between the V-shaped pressing block 11 and the cylinder head workpiece 0 is evenly stressed, and restrict the cylinder head workpiece 0 to rotate along the central positioning shaft 14.

[0036] External threads are machined at the lower ends of the rear connecting rod 13 and the front connecting rod 15, and they are symmetrically installed at the two connecting rod installation threaded holes on the base 16. The upper end of the rear connecting rod 13 has a symmetric stepped structure. A connecting hole is machined on the side of the stepped protrusion. The rear connecting rod 13 is connected to the rear groove of the pressure plate 8 through the 10 mm cylindrical pin 9 to ensure that the pressure plate 8 can flip up and down without restriction. The upper end of the front connecting rod 15 has a groove structure, and a connecting hole is machined on the side. It is connected to the lower end of the articulated bolt 12 through the 10 mm cylindrical pin 9. The upper end of the articulated bolt 12 passes through the front groove of the pressure plate 8 and is connected to the combination washer 7 and the lock nut 6. The articulated bolt 12 can be perpendicular to the base 15 under the limit of the front groove. The functions of the rear connecting rod 13 and the front connecting rod 15 are to transmit the downward pressure for the fixture and provide a supporting effect.

[0037] In this embodiment, the connecting seat 4, the base 16, the pressing plate 8, the rear connecting rod 13, the front connecting rod 15, the knuckle bolt 12, and the V-shaped pressing block are all subjected to relatively large forces in the entire tooling. Therefore, 40Cr bar stock or sheet material is selected as the processing material, and the quenched and tempered hardness is HRC38 - 42. The counterweight 3, the center positioning shaft 14, the washer 2, and the combined washer 7 are made of 45 steel material, and the quenched and tempered hardness is HRC28 - 32. They are processed according to the design requirements. The 5mm positioning pin 5, the 10mm cylindrical pin 9, and the 8mm cylindrical pin 10 are standard hardened cylindrical pins of GB119, and the locking nut 12 is a standard 9-grade high-strength pressing plate nut.

[0038] When using the above-mentioned tooling fixture for turning the oil cylinder head lug to process, the tooling fixture is connected to the Morse internal taper of the lathe spindle through the Morse No. 6 taper shank at the left end of the connecting seat 4 to ensure firmness, and a pull rod is installed and tightened with the tail end of the lathe spindle. Insert the inner hole of the cover body part of the oil cylinder head workpiece 0 into the center positioning shaft 14, and the bottom surface contacts the base 16. Rotate the side surface of the lug part to be approximately parallel to the X-axis of the machine tool. Flip the pressing plate 8 so that the V-shaped pressing block 11 contacts the top of the lug of the oil cylinder head workpiece 0. Flip the knuckle bolt 12 into the front groove of the pressing plate 8 and tighten the locking nut 6 with a socket wrench. At this time, the oil cylinder head workpiece 0 is completely constrained on the tooling fixture, and then the oil cylinder head workpiece 0 can be processed. After the processing is completed, loosen the locking nut 6 in the reverse direction, flip the knuckle bolt 12, lift the pressing plate 8, and take out the oil cylinder head workpiece 0 axially upward along the center positioning shaft 14. Simply clean the positioning surface of the tooling fixture, and then the next oil cylinder head workpiece 0 can be clamped and processed.

[0039] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A fixture for turning a cylinder head lifting lug, characterized in that: The fixture comprises a connecting seat, a base, a counterweight, a center positioning shaft, a pressure plate, a V-shaped pressure block, a rear connecting rod, a front connecting rod and a movable bolt; wherein, The left end of the connecting seat is a tapered handle structure, which is used to cooperate with the inner cone of the lathe spindle. The center of the left end of the tapered handle is processed with an internal threaded hole for installing the spindle pull rod; the right end of the connecting seat is a rectangular structure connected to the tapered handle structure; the upper plane of the rectangular block is processed with a threaded hole for installing the counterweight block, and the lower plane of the rectangular block is processed with a threaded hole for connecting to the base; The base is a rectangular structure, with a through countersunk hole processed on the left end. The hexagon socket bolt is inserted into the countersunk hole of the base and screwed into the threaded hole on the lower plane of the right end of the rectangular block of the connecting seat to fix the connecting seat to the base; a center positioning hole is processed in the middle position of the right end of the base for installing the center positioning shaft, and connecting rod installation threaded holes for connecting the rear connecting rod and the front connecting rod are processed on both sides of the center positioning hole; The counterweight block is a rectangular parallelepiped structure, with through countersunk holes processed on the upper and lower planes. The hexagon socket bolts are inserted into the countersunk holes in sequence and screwed into the threaded holes on the upper plane of the rectangular parallelepiped at the right end of the connecting seat to fix the counterweight block to the connecting seat; The center positioning shaft is a stepped shaft structure, the lower end of the stepped shaft is connected to the center positioning hole of the base through an interference fit, and the upper end of the stepped shaft forms a clearance fit with the inner hole at the lower end of the cylinder cover workpiece; The pressing plate is a rectangular parallelepiped structure with support arms at both ends. The rear end support arm of the pressing plate is processed with a rear end groove for connecting with the rear connecting rod, and a connecting hole is processed on the side of the rear end groove. After the cylindrical pin is inserted into the connecting hole, it is connected with the upper end connecting hole of the rear connecting rod; the front end support arm of the pressing plate is processed with a front end groove for the joint bolt to pass through; the bottom of the pressing plate is an arc groove structure, and a connecting hole is processed on the side of the arc groove. The upper end arc of the V-shaped pressing block is inserted into the bottom arc groove of the pressing plate, and the cylindrical pin is inserted into the connecting hole on the side of the arc groove and the connecting hole on the side of the V-shaped pressing block to connect the V-shaped pressing block to the pressing plate. The depth and width of the arc groove are greater than the upper end arc of the V-shaped pressing block. The upper end of the V-shaped pressing block is an arc structure, and the side of the arc structure is processed with a connecting hole for inserting a cylindrical pin; the lower end of the V-shaped pressing block is a V-shaped groove, which is used to contact the cover ring part of the cylinder head workpiece; the V-shaped pressing block and the pressing plate are connected in a floating manner. When the pressing plate is pressed down, the V-shaped pressing block can automatically fine-tune the angle to ensure that the contact surface between the V-shaped pressing block and the cylinder head workpiece is evenly stressed, and the cylinder head workpiece is constrained to rotate along the central positioning axis; The lower ends of the rear connecting rod and the front connecting rod are both processed with external threads, and are symmetrically installed on the two connecting rod mounting threaded holes of the base; the upper end of the rear connecting rod is a symmetrical step structure, and the side surfaces of the protruding parts of the step are processed with connecting holes, and the rear connecting rod is connected to the rear end groove of the pressure plate through a cylindrical pin; the upper end of the front connecting rod is a groove structure, and the side surfaces are processed with connecting holes, which is connected to the lower end of the live bolt through a cylindrical pin, and the upper end of the live bolt passes through the front end groove of the pressure plate and is connected to the locking nut, and the live bolt can be perpendicular to the base under the limit of the front end groove.

2. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: The left end of the connecting seat is a Morse No. 6 taper handle structure.

3. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: For the machining accuracy of 60±0.05mm from the bottom surface of the cylinder head workpiece to the center of the lifting ear, the distance from the lower plane of the right end cuboid of the connecting seat to the center of the tapered shank is 60±0.015mm.

4. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: Positioning holes for inserting positioning pins are processed on the lower plane of the right end of the connecting seat and the left end of the base, and the positioning pins are respectively inserted into the positioning holes.

5. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: The inner hole clearance between the upper end of the step shaft and the lower end of the cylinder cover workpiece is controlled within 0.025mm.

6. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: The connecting seat, base, pressure plate, rear connecting rod, front connecting rod, live bolt and V-shaped pressure block are made of 40Cr bars or plates with a quenched and tempered hardness of HRC38-42.

7. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: The counterweight block and center positioning shaft are made of 45# steel with tempering hardness of HRC28~32.

8. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: The cylindrical pins are made of GB119 hardened cylindrical pin standard parts.

9. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: The locking nut is made of grade 9 high-strength pressure plate nut standard part.

10. The jig for turning the cylinder head lifting lug according to claim 1, characterized in that: After the hexagon socket bolt is put on the washer, it is inserted into the countersunk hole of the counterweight block and screwed into the threaded hole on the upper plane of the right end rectangular block of the connecting seat; the upper end of the movable bolt passes through the front end groove of the pressure plate and is connected with the washer and the locking nut; the washer is made of No. 45 steel with a tempering hardness of HRC28~32.

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