Tool clamp for turning oil cylinder cover lifting lug

Abstract

The utility model 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, therefore, 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 parts of the same type and different sizes, and therefore the clamp cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of machining technology, specifically relating to a tooling fixture for turning cylinder head lifting lugs. Background Technology

[0002] Hydraulic cylinders, as key actuators in hydraulic systems, are widely used in various engineering machinery fields. The cylinder head is a crucial connection point between the cylinder body and other components, and its machining quality directly affects the cylinder's operational reliability. The cylinder head typically has a two-way cylindrical structure, resembling a lifting lug. This lug is generally approximately annular, serving as a connection point for holes, sealing grooves, and oil passages for other components. Strict requirements are placed on the dimensional accuracy, positional accuracy, and surface roughness of the holes and grooves in the lifting lug. During the machining of the cylinder head lifting lug, the design of the tooling fixture is paramount. It must not only ensure the positioning accuracy of the cylinder head during machining but also withstand the cutting forces and other external forces. Traditional tooling fixtures suffer from insufficient positioning accuracy, low efficiency, and poor versatility. Therefore, designing a precise and efficient tooling fixture for machining the cylinder head lifting lug is essential. Utility Model Content

[0003] (a) Technical problems to be solved

[0004] This utility model proposes a tooling fixture for turning cylinder head lifting lugs to solve the technical problems of low positioning accuracy, poor clamping efficiency and insufficient versatility in the cylinder head machining process.

[0005] (II) Technical Solution

[0006] To solve the above-mentioned technical problems, this utility model proposes a tooling fixture for turning cylinder head lifting lugs. The tooling fixture includes a connecting seat, a base, a counterweight, a central positioning shaft, a pressure plate, a V-shaped pressure block, a rear connecting rod, a front connecting rod, and a hinge bolt.

[0007] The left end of the connecting seat is a tapered shank structure, which is used to connect with the inner tapered body of the lathe spindle. The center of the left end of the tapered shank has an internal threaded hole for installing the spindle tie rod. The right end of the connecting seat is a cuboid structure that connects with the tapered shank structure. The upper surface of the cuboid has a threaded hole for installing the counterweight, and the lower surface of the cuboid has a threaded hole for connecting to the base.

[0008] The base is a cuboid structure with a through countersunk hole machined at the left end. An internal hex bolt is inserted into the countersunk hole of the base and screwed into the threaded hole on the lower surface of the right cuboid of the connecting seat to fix the connecting seat to the base. A center positioning hole is machined at the middle of the right end of the base for installing the center positioning shaft. Connecting rod mounting threaded holes for connecting the rear connecting rod and the front connecting rod are machined on both sides of the center positioning hole.

[0009] The counterweight is a cuboid structure with through countersunk holes machined on the upper and lower surfaces. Hexagonal socket bolts are inserted into the countersunk holes and screwed into the threaded holes on the upper surface of the right cuboid of the connecting seat to fix the counterweight to the connecting seat.

[0010] The center positioning shaft has 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 head workpiece.

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

[0012] The upper end of the V-shaped pressure block has an arc structure, and the side of the arc structure is machined with a connecting hole for inserting a cylindrical pin; the lower end of the V-shaped pressure block has a V-groove for contacting the cover ring part of the cylinder head workpiece; the V-shaped pressure block and the pressure plate are connected by a floating connection. When the pressure plate is pressed down, the V-shaped pressure block can automatically adjust its angle to ensure that the contact surface between the V-shaped pressure block and the cylinder head workpiece is evenly stressed, and to constrain the cylinder head workpiece to rotate along the central positioning axis.

[0013] Both the rear and front connecting rods have external threads machined at their lower ends and are symmetrically installed on the two connecting rod mounting threaded holes on the base. The upper end of the rear connecting rod has a symmetrical stepped structure, and the side of the protruding part of the step has a connecting hole machined. The rear connecting rod is connected to the rear end groove of the pressure plate by a cylindrical pin. The upper end of the front connecting rod has a groove structure, and the side has a connecting hole machined. It is connected to the lower end of the hinge bolt by a cylindrical pin. The upper end of the hinge bolt passes through the front end groove of the pressure plate and is connected to the lock nut. The hinge bolt can be perpendicular to the base under the limitation of the front end groove.

[0014] Furthermore, the left end of the connector is a Morse code 6 cone-handle structure.

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

[0016] Furthermore, the lower plane of the right cuboid of the connecting seat and the left end of the base are machined with positioning holes for inserting positioning pins, and positioning pins are inserted into the positioning holes respectively.

[0017] Furthermore, the gap between the upper end of the stepped shaft and the lower end of the cylinder head workpiece is controlled within 0.025mm.

[0018] Furthermore, the connecting seat, base, pressure plate, rear connecting rod, front connecting rod, hinge bolt, and V-shaped pressure block are made of 40Cr bar stock or plate, with a tempered hardness of HRC38~42.

[0019] Furthermore, the counterweight and the central positioning shaft are made of 45 steel with a tempered hardness of HRC28~32.

[0020] Furthermore, the cylindrical pins are selected from GB119 hardened cylindrical pin standard parts.

[0021] Furthermore, the locking nut is a standard grade 9 high-strength pressure plate nut.

[0022] Furthermore, after the socket head cap screw is fitted with a washer, it is inserted into the countersunk hole of the counterweight and screwed into the threaded hole on the upper surface of the right cuboid of the connecting seat; the upper end of the hinge bolt passes through the front groove of the pressure plate and is connected to the washer and the lock nut; the washer is made of 45 steel with a tempered hardness of HRC28~32.

[0023] (III) Beneficial Effects

[0024] This invention discloses a tooling fixture for turning cylinder head lifting lugs, mainly comprising a connecting seat, a base, a counterweight, a central positioning shaft, a pressure plate, a V-shaped pressure block, a rear connecting rod, a front connecting rod, and a hinge bolt. During cylinder head turning, the bottom of the workpiece is fixed on the central positioning shaft, and the top of the ring of the lifting lug contacts the V-shaped pressure block. The V-shaped pressure block is connected to the pressure plate via a cylindrical pin. Each side of the pressure plate has a support arm, which is connected to the front and rear connecting rods via grooves. By flipping the pressure plate, the V-shaped pressure block contacts the top of the lifting lug of the cylinder head workpiece, and the workpiece is secured to the tooling fixture by tightening the hinge bolt. This tooling fixture enables automatic workpiece alignment, thereby reducing positioning errors. Furthermore, the design of the central positioning shaft ensures the fixture's versatility, making it suitable for machining parts of the same type but different sizes, thus reducing fixture costs. Attached Figure Description

[0025] Figure 1 This is an overall structural diagram of the tooling fixture of this utility model in its working state;

[0026] Figure 2 This is an overall structural diagram of the tooling fixture of this utility model in the state of the workpiece to be clamped;

[0027] Figure 3 This is an exploded view of the tooling fixture of this utility model in its working state. Detailed Implementation

[0028] To make the objectives, contents, and advantages of this utility model clearer, the specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0029] This embodiment proposes a tooling fixture for turning cylinder head lifting lugs, the structure of which is as follows: Figures 1-3 As shown, it mainly includes a connecting seat 4, a base 16, a 6mm positioning pin 5, a counterweight block 3, a central positioning shaft 14, a pressure plate 8, a V-shaped pressure block 11, a rear connecting rod 13, a front connecting rod 15, and a hinge bolt 12.

[0030] The left end of the connecting seat 4 is a Morse code 6 tapered shank structure, used to connect with the inner tapered body of the lathe spindle. An M16 internal thread hole is machined at the center of the left end of the tapered shank for installing the spindle tie rod, ensuring a safe connection. The right end of the connecting seat 4 is a cuboid structure that connects to the tapered shank structure. To ensure a machining accuracy of 60±0.05mm from the bottom surface of the cylinder head workpiece 0 to the center of the lifting lug, the distance from the lower plane of the cuboid to the center of the tapered shank is designed to be 60±0.015mm to improve the positioning accuracy of the fixture. The upper plane of the cuboid has two threaded holes for installing the counterweight 3, and the lower plane has three threaded holes for connecting to the base 16 and two positioning holes for inserting the 6mm positioning pin 5.

[0031] The base 16 is a cuboid structure with three through countersunk holes and two locating holes machined on its left end. A 6mm locating pin 5 is inserted into each of the two locating holes. Three hex socket head cap bolts 1, each fitted with a single washer 2, are inserted into the three countersunk holes of the base 16 and screwed into the three threaded holes on the lower surface of the right cuboid of the connecting seat 4, thus fixing the connecting seat 4 to the base 16. The two 6mm locating pins 5 are inserted into the two locating holes on the lower surface of the right cuboid of the connecting seat 4 to prevent relative displacement between the base 16 and the connecting seat 4 during machining, which could cause errors in the workpiece's form and position tolerances. A center locating hole is machined at the middle of the right end of the base 16 for mounting the center locating shaft 14. Connecting rod mounting threaded holes are machined on both sides of the center locating hole for connecting the rear connecting rod 13 and the front connecting rod 15.

[0032] The counterweight 3 is a cuboid structure with two through countersunk holes machined on its upper and lower surfaces. Two hexagon socket head cap bolts 1, fitted with washers 2, are inserted into the two countersunk holes and screwed into the two threaded holes on the upper surface of the right end of the cuboid of the connecting seat 4, thus fixing the counterweight 3 to the connecting seat 4. The counterweight 3 is used to balance the center of gravity of the entire tooling fixture during high-speed rotation, ensuring the machining accuracy and safety of the product.

[0033] The center positioning shaft 14 is a stepped shaft structure. The lower end of the stepped shaft is connected to the center positioning hole of the base 16 through an 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. The clearance is controlled within 0.025mm. By replacing the center positioning shaft 14 with different outer diameters, cylinder head workpieces 0 with different diameters can be clamped and positioned.

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

[0035] The upper end of the V-shaped pressure block 11 has an arc structure, and the side of the arc structure is machined with a connecting hole for inserting an 8mm cylindrical pin 10. The lower end of the V-shaped pressure block 11 has a 90° V-groove for contacting the cover ring of the cylinder head workpiece 0. Without interference during machining, the V-groove is made as close as possible to the width of the cover ring. Because the cylinder head workpiece 0 is made of casting material, the outer surface of the lifting lug is irregular. The V-shaped pressure block 11 and the pressure plate 8 are connected by a floating connection. When the pressure plate 8 is pressed down, the V-shaped pressure block 11 can automatically adjust its angle to ensure uniform force on the contact surface between the V-shaped pressure block 11 and the cylinder head workpiece 0, and to constrain the cylinder head workpiece 0 to rotate along the central positioning axis 14.

[0036] Both the rear connecting rod 13 and the front connecting rod 15 have external threads machined at their lower ends, symmetrically mounted on the base 16 at the threaded mounting holes. The upper end of the rear connecting rod 13 has a symmetrical stepped structure, with connecting holes machined on the side of the protruding part of the step. A 10mm cylindrical pin 9 connects the rear connecting rod 13 to the rear groove of the pressure plate 8, ensuring that the pressure plate 8 can rotate freely. The upper end of the front connecting rod 15 has a groove structure with connecting holes machined on the side. A 10mm cylindrical pin 9 connects the front connecting bolt 12 to its lower end. The upper end of the connecting bolt 12 passes through the front groove of the pressure plate 8 and connects to the combination washer 7 and the lock nut 6. The connecting bolt 12 can be perpendicular to the base 15 under the limitation of the front groove. The function of the rear connecting rod 13 and the front connecting rod 15 is to transmit downward pressure and provide support for the fixture.

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

[0038] When machining the cylinder head lifting lug using the aforementioned tooling fixture, the tooling fixture is connected to the Morse taper 6 on the left end of the connecting seat 4 to the Morse inner cone of the lathe spindle to ensure a secure connection. A tie rod is added to tighten it to the tail end of the lathe spindle. The inner hole of the cylinder head workpiece 0 is inserted into the center positioning shaft 14, with the bottom surface contacting the base 16. The side of the lifting lug is rotated approximately parallel to the X-axis of the machine tool. The pressure plate 8 is flipped so that the V-shaped pressure block 11 is aligned with the top of the lifting lug of the cylinder head workpiece 0. With the end in contact, flip the hinge bolt 12 into the front groove of the pressure plate 8 and tighten the locking nut 6 with a socket wrench. At this time, the cylinder head workpiece 0 is completely constrained on the tooling fixture, and the cylinder head workpiece 0 can be processed. After processing, loosen the locking nut 6 in the opposite direction, flip the hinge bolt 12, lift the pressure plate 8, and take the cylinder head workpiece 0 out axially upward along the central positioning shaft 14. After simple cleaning of the positioning surface of the tooling fixture, the next cylinder head workpiece 0 can be clamped and processed.

[0039] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A tooling fixture for turning cylinder head lifting lugs, characterized in that, The tooling fixture includes a connecting seat, a base, a counterweight, a central positioning shaft, a pressure plate, a V-shaped pressure block, a rear connecting rod, a front connecting rod, and a hinge bolt; wherein... The left end of the connecting seat is a tapered shank structure, which is used to connect with the inner tapered body of the lathe spindle. The center of the left end of the tapered shank has an internal threaded hole for installing the spindle tie rod. The right end of the connecting seat is a cuboid structure that connects with the tapered shank structure. The upper surface of the cuboid has a threaded hole for installing the counterweight, and the lower surface of the cuboid has a threaded hole for connecting to the base. The base is a cuboid structure with a through countersunk hole machined at the left end. An internal hex bolt is inserted into the countersunk hole of the base and screwed into the threaded hole on the lower surface of the right cuboid of the connecting seat to fix the connecting seat to the base. A center positioning hole is machined at the middle of the right end of the base for installing the center positioning shaft. Connecting rod mounting threaded holes for connecting the rear connecting rod and the front connecting rod are machined on both sides of the center positioning hole. The counterweight is a cuboid structure with through countersunk holes machined on the upper and lower planes. Hexagonal socket bolts are inserted into the countersunk holes and screwed into the threaded holes on the upper plane of the right cuboid of the connecting seat to fix the counterweight to the connecting seat. The center positioning shaft has 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 head workpiece. The pressure plate is a cuboid structure with support arms at both the front and rear ends. The rear support arm of the pressure plate has a rear groove for connecting with the rear connecting rod. The side of the rear groove has a connecting hole. After the cylindrical pin is inserted into the connecting hole, it connects with the upper connecting hole of the rear connecting rod. The front support arm of the pressure plate has a front groove for the hinge bolt to pass through. The bottom of the pressure plate is an arc groove structure. The side of the arc groove has a connecting hole. The upper arc of the V-shaped pressure block is inserted into the bottom arc groove of the pressure plate. 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 pressure block to connect the V-shaped pressure block to the pressure plate. The depth and width of the arc groove are greater than the upper arc of the V-shaped pressure block. The upper end of the V-shaped pressure block has an arc structure, and the side of the arc structure is machined with a connecting hole for inserting a cylindrical pin; the lower end of the V-shaped pressure block has a V-groove for contacting the cover ring part of the cylinder head workpiece; the V-shaped pressure block and the pressure plate are connected by a floating connection. When the pressure plate is pressed down, the V-shaped pressure block can automatically adjust its angle to ensure that the contact surface between the V-shaped pressure block and the cylinder head workpiece is evenly stressed, and to constrain the cylinder head workpiece to rotate along the central positioning axis. Both the rear and front connecting rods have external threads machined at their lower ends and are symmetrically installed on the two connecting rod mounting threaded holes on the base. The upper end of the rear connecting rod has a symmetrical stepped structure, and the side of the protruding part of the step has a connecting hole machined. The rear connecting rod is connected to the rear end groove of the pressure plate by a cylindrical pin. The upper end of the front connecting rod has a groove structure, and the side has a connecting hole machined. It is connected to the lower end of the hinge bolt by a cylindrical pin. The upper end of the hinge bolt passes through the front end groove of the pressure plate and is connected to the lock nut. The hinge bolt can be perpendicular to the base under the limitation of the front end groove.

2. The tooling fixture for machining cylinder head lifting lugs as described in claim 1, characterized in that, The left end of the connector is a Morse code 6 cone handle structure.

3. The tooling fixture for machining cylinder head lifting lugs as described in 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 lug, the distance from the lower plane of the right end cuboid of the connecting seat to the center of the cone shank is 60±0.015mm.

4. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, The lower plane of the right cuboid of the connector and the left end of the base are machined with positioning holes for inserting positioning pins, and positioning pins are inserted into the positioning holes respectively.

5. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, The gap between the upper end of the stepped shaft and the lower end of the cylinder head workpiece is controlled within 0.025mm.

6. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, The connecting seat, base, pressure plate, rear connecting rod, front connecting rod, hinge bolt and V-shaped pressure block are made of 40Cr bar stock or plate, and the tempering hardness is HRC38~42.

7. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, The counterweight and the central positioning shaft are made of 45 steel with a tempered hardness of HRC28~32.

8. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, The cylindrical pins are selected from GB119 hardened cylindrical pin standard parts.

9. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, The locking nut is a standard part of grade 9 high-strength pressure plate nut.

10. The tooling fixture for turning cylinder head lifting lugs as described in claim 1, characterized in that, After the socket head cap screw is fitted with a washer, it is inserted into the countersunk hole of the counterweight and screwed into the threaded hole on the upper surface of the right cuboid of the connecting seat; the upper end of the hinge bolt passes through the front groove of the pressure plate and is connected to the washer and the lock nut; the washer is made of 45 steel with a tempered hardness of HRC28~32.

Images