An automobile engine cooling water pump shell mounting surface machining fixing tool and fixing method

Abstract

The application discloses a kind of automobile engine cooling water pump shell mounting surface processing fixing tool and fixing method, fixing tool includes including connecting disc, positioning pin, positioning rod, tensioning mechanism, support rod;Connecting disc front is provided with mounting hole I, to install positioning pin, positioning rod, connecting disc center is provided with mounting hole II to install tensioning mechanism, connecting disc front is provided with screw hole I to connect support rod;The tensioning mechanism includes expansion sleeve, expansion shaft, pull rod, connecting disc is fixed positioning by positioning pin positioning rod tensioning mechanism with the workpiece to be processed, compared with traditional processing tool, the device can realize the positioning of shell blank bearing hole of different tolerance problem by designing tensioning mechanism, greatly improve workpiece processing efficiency and product quality, reduce production cost.

Description

Technical Field

[0001] This invention relates to the field of machining equipment, specifically to a machining and fixing fixture and method for the mounting surface of an automotive engine cooling water pump housing. Background Technology

[0002] The water pump housing mounting surface is the primary machining reference for other parts of the automotive engine water pump housing, making its machining quality particularly important. The water pump housing is made of die-cast aluminum alloy using a die-casting process. Since machining the housing mounting surface is the first machining step, the selection of the corresponding machining positioning position is crucial. Currently, the commonly used machining fixing device typically uses the bearing hole, with machining allowance left after the housing blank is die-cast, as the positioning point. The machining fixture is equipped with a mandrel of fixed dimensions for initial centering of the bearing hole, and locating pins are used for final positioning. This machining fixture and positioning method has the following technical defects: Because the parts to be processed are die-cast housing blanks, the bearing hole size tolerances of the housing blanks are large, and there are also differences between different blanks. It is not possible to guarantee that the bearing hole of the housing blank and the fixed mandrel on the tooling will maintain a good fit. This leads to an increase in the scrap rate of the processed products, an increase in quality costs, and sometimes it is necessary to stop the machine on-site to repair the outer diameter of the mandrel or replace the mandrel, causing downtime and reduced production efficiency, and increased production costs. Summary of the Invention

[0003] To solve the above-mentioned technical problems, improve the processing efficiency and quality of the engine coolant pump housing mounting surface, and reduce production costs, this invention provides a machining and fixing fixture and method for the mounting surface of an automotive engine coolant pump housing.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A tooling for machining and fixing the mounting surface of an automotive engine cooling water pump housing includes a connecting plate, a locating pin, a locating rod, a tensioning mechanism, and a support rod. The front of the connecting plate is provided with mounting hole I for installing positioning pins and positioning rods, the center of the connecting plate is provided with mounting hole II for installing tensioning mechanism, and the front of the connecting plate is provided with threaded hole I for connecting support rods. The tensioning mechanism includes an expansion sleeve, an expansion shaft, and a tie rod. The expansion sleeve includes an integrally connected bushing, flange, expansion cylinder, and elastic flap. The bushing is connected to the mounting hole II of the connecting plate through a transition fit and is fixedly connected to the connecting plate through the flange. The flange has three bolt holes I evenly distributed on it, and the connecting plate is provided with threaded holes II. The flange is fixedly connected to the connecting plate through screws I.

[0005] The elastic flaps are six pieces evenly distributed at the end of the expansion cylinder, with gaps between them, and the inner cavity formed by the expansion cylinder and the elastic flaps is frustoconical in shape. The tie rod passes through the bushing and the expansion cylinder, and is clearance-fitted with the bushing. One end of the tie rod is provided with a threaded hole, and is fixedly connected to the expansion shaft by screw II. The expansion shaft is a frustoconical shape with bolt hole II. When the tie rod moves to the left, it causes the expansion shaft to contact the inner side of the elastic flap and open the elastic flap.

[0006] Furthermore, stress-relieving holes are provided at the connection between the root of the elastic flap and the expansion cylinder to increase the toughness of the elastic flap.

[0007] Furthermore, the lower outer wall of the elastic flap is thinned to facilitate deformation under stress; the maximum outer diameter of the outer surface of the elastic flap in its natural state is the same as the outer diameter of the expansion cylinder; and the outer end of the elastic flap is chamfered.

[0008] Furthermore, the connection between the expansion cylinder, bushing, and flange is cleaned.

[0009] Furthermore, one end of the positioning rod and the positioning pin is interference-fitted with the mounting hole I, and the other end of the positioning pin and the mounting hole I is provided with a positioning shaft, which is clearance-fitted with the mounting hole of the housing blank to be processed.

[0010] One end of the support rod is provided with a screw, which is connected to a nut. The screw is connected to the threaded hole I of the connecting plate, and the other end of the support rod is in contact with the shell blank.

[0011] The connecting plate has three bolt holes (Ⅲ) on its outer perimeter, and an inner stop is provided on the back of the connecting plate.

[0012] Furthermore, the two mounting holes I and the two threaded holes I correspond to the positions of the four mounting holes on the positioned housing blank.

[0013] A method for fixing a housing blank using a machining fixture on the mounting surface of an automotive engine coolant pump housing, comprising the following steps: S1: The expansion sleeve, positioning pin, positioning rod, and support rod are installed on the connecting plate. The support rod is rotated to the deepest point of threaded hole I. The nut on the support rod is not tightened and does not contact the connecting plate. S2: The inner stop on the connecting plate is connected to the transition plate of the hydraulic CNC lathe and is fastened with three evenly distributed M10 bolts; S3: The tie rod passes through the expansion sleeve, and its left extended section is connected to the piston rod of the hydraulic cylinder of the hydraulic CNC lathe. The connection method is threaded connection. The right end of the tie rod is fixedly connected to the expansion shaft by screw II. The expansion shaft does not contact the expansion sleeve. S4: With the mounting surface of the housing blank facing outwards, that is, after the housing contacts the connecting plate, the mounting holes are far away from the connecting plate. There are a total of four mounting holes on the housing. Two of the mounting holes used for positioning are fitted into the positioning pins and positioning rods on the connecting plate, respectively. At the same time, the bearing hole of the housing blank enters the expansion sleeve. Push the housing inwards until the end face of the bearing hole of the housing hits the flange of the expansion sleeve and can no longer be pushed. S5: Rotate the two support rods outwards to adjust their heights, ensuring that the outer end face of the support rods is in effective contact with the two mounting holes of the housing. Tighten the support rods and connecting plate with nuts M12. S6: The piston rod of the hydraulic cylinder of the CNC lathe moves to the left, pulling the tie rod to the left. The expansion shaft fixed on the tie rod also moves to the left. The outer conical surface of the expansion shaft connects with the inner conical surface of the expansion sleeve. As the tie rod continues to move to the left, the expansion shaft opens up the six elastic petals on the expansion sleeve. The outer circular surface of the elastic petals is in close contact with the inner wall of the shaft hole of the housing blank, achieving precise positioning. S7: Start the lathe and begin machining. After machining is completed, the piston rod of the CNC lathe hydraulic cylinder moves to the right, pushing the pull rod to the right, and the expansion shaft also moves to the right. The expansion shaft separates from the expansion sleeve, the elastic flap of the expansion sleeve returns to its original position, and the expansion sleeve separates from the bearing hole of the housing. The workpiece is removed, and the machining of the next workpiece begins.

[0014] The beneficial effects of this invention are as follows: Compared with traditional fixed fixtures and methods, this invention has made ingenious improvements to the fixed fixtures. By designing a special tensioning mechanism, it can realize the positioning of bearing holes in shell blanks that can adapt to different tolerance problems, which greatly improves workpiece processing efficiency and product quality, and reduces production costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the connecting disk structure according to an embodiment of the present invention; Figure 2 for Figure 1 AA diagram; Figure 3 This is a schematic diagram of the expansion sleeve structure according to an embodiment of the present invention. Figure 4 A schematic diagram of the finished mounting surface of the engine water pump housing. 1-Connecting disc, 2-Nut, 3-Support rod, 4-Expansion sleeve, 5-Tie rod, 6-Screw I, 7-Expansion shaft, 8-Screw II, 9-Locking pin, 10-Locking rod, 11-Stop, 41-Shaft sleeve, 42-Flange, 43-Expansion cylinder, 44-Elastic flap, 45-Stress relief hole. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings: A machining and fixing fixture for the mounting surface of an automotive engine cooling water pump housing includes a connecting plate 1, a positioning pin 9, a positioning rod 10, a tensioning mechanism, and a support rod 3; As attached Figure 1 The connecting plate 1 shown has a mounting hole I on its front side for mounting the positioning pin 9 and the positioning rod 10. The connecting plate 1 has a mounting hole II in its center for mounting the tensioning mechanism. The connecting plate 1 has a threaded hole I on its front side for connecting the support rod 3. like Figure 2As shown, the tensioning mechanism includes an expansion sleeve 4, an expansion shaft 7, and a tie rod 5. The expansion sleeve 4 includes an integrally connected bushing 41, a flange 42, an expansion cylinder 43, and an elastic flap 44. The bushing 41 is connected to the mounting hole II of the connecting plate 1 through a transition fit, and is fixedly connected to the connecting plate 1 through the flange 42. The flange has three bolt holes I evenly distributed on it, and the connecting plate 1 is provided with threaded holes II. The flange is fixedly connected to the connecting plate 1 through screws I6.

[0017] The elastic flaps 44 are six pieces evenly distributed at the end of the expansion cylinder, and there are gaps between the elastic flaps 44. The inner cavity formed by the expansion cylinder 43 and the elastic flaps 44 is frustoconical. The pull rod 5 passes through the bushing and the expansion cylinder, and is clearance-fitted with the bushing. One end of the pull rod 5 is provided with a threaded hole, and is fixedly connected to the expansion shaft 7 by screw II 8. The expansion shaft 7 is a frustoconical shape with bolt hole II. When the pull rod 5 moves to the left, it causes the expansion shaft 7 to contact the inner side of the elastic flap and open the elastic flap.

[0018] like Figure 3 As shown, a stress-relieving hole is provided at the connection between the root of the elastic flap and the expansion cylinder to increase the toughness of the elastic flap; the lower outer wall of the elastic flap 44 is thinned to facilitate the deformation of the elastic flap under stress; the maximum outer diameter of the outer surface of the elastic flap 44 in its natural state is the same as the outer diameter of the expansion cylinder 43; the outer end of the elastic flap 44 is chamfered.

[0019] Furthermore, the connection between the expansion cylinder 43 and the bushing 42 and the flange 42 is cleaned.

[0020] Furthermore, one end of the positioning rod 10 and the positioning pin 9 is interference-fitted with the mounting hole I, and the other end of the positioning pin 9 and the mounting hole I is provided with a positioning shaft, which is clearance-fitted with the mounting hole of the housing blank to be processed.

[0021] One end of the support rod 3 is provided with a screw, which is connected to a nut 2. The screw is connected to the threaded hole I of the connecting disc 1, and the other end of the support rod 3 is in contact with the shell blank.

[0022] The outer periphery of the connecting plate 1 is provided with three bolt holes Ⅲ, and the back of the connecting plate 1 is provided with an inner stop.

[0023] Furthermore, the two mounting holes I and the two threaded holes I correspond to the positions of the four mounting holes on the positioned housing blank, as follows: Figure 4 As shown, the positioning rod and positioning pin correspond to the mounting holes A and C to prevent the housing blank from rotating, and the top of the support rod contacts the lower end of the mounting holes B and D to stabilize the housing blank.

[0024] A method for fixing a housing blank using a machining fixture on the mounting surface of an automotive engine coolant pump housing, comprising the following steps: S1: The expansion sleeve 4, positioning pin 9, positioning rod 10, and support rod 3 are installed on the connecting plate 1. The support rod 3 is rotated to the deepest point of the threaded hole I. The nut 2 on the support rod 3 is not tightened and does not contact the connecting plate 1. S2: The inner stop on the connecting plate 1 is connected to the transition plate of the hydraulic CNC lathe and is fastened with three evenly distributed M10 bolts; S3: The tie rod 5 passes through the expansion sleeve 4, and its left extended section is connected to the piston rod of the hydraulic cylinder of the hydraulic CNC lathe. The connection method is threaded connection. The right end of the tie rod 5 is fixedly connected to the expansion shaft 7 by screw II8. The expansion shaft 7 does not contact the expansion sleeve 4. S4: With the mounting surface of the housing blank facing outwards, that is, after the housing contacts the connecting plate 1, the mounting holes are far away from the connecting plate 1. There are a total of four mounting holes on the housing. Two of the mounting holes used for positioning are fitted into the positioning pins 9 and positioning rods 10 on the connecting plate 1, respectively. At the same time, the bearing hole of the housing blank enters the expansion sleeve 4. Push the housing inwards until the end face of the bearing hole of the housing hits the flange of the expansion sleeve 4 and can no longer be pushed. S5: Rotate the two support rods 3 outwards to adjust their heights, ensuring that the outer end face of the support rod 3 is in effective contact with the two mounting hole ends of the housing. Tighten the support rod 3 and the connecting plate 1 with nut 2M12. S6: The piston rod of the hydraulic cylinder of the CNC lathe moves to the left, pulling the tie rod 5 to the left. The expansion shaft 7 fixed on the tie rod 5 also moves to the left. The outer conical surface of the expansion shaft 7 connects with the inner conical surface of the expansion sleeve 4. As the tie rod 5 continues to move to the left, the expansion shaft 7 opens up the six elastic petals on the expansion sleeve 4. The outer circular surface of the elastic petals is in close contact with the inner wall of the shaft hole of the housing blank, achieving precise positioning. S7: Start the lathe and begin machining. After machining is completed, the piston rod of the CNC lathe hydraulic cylinder moves to the right, pushing the pull rod 5 to the right. The expansion shaft 7 also moves to the right, separating the expansion shaft 7 from the expansion sleeve 4. The elastic flap of the expansion sleeve 4 returns to its original position, separating the expansion sleeve 4 from the housing bearing hole. Remove the workpiece and proceed with the machining of the next workpiece.

[0025] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention without creative effort.

Claims

1. A tooling for machining and fixing the mounting surface of an automotive engine cooling water pump housing, characterized in that: It includes a connecting plate, positioning pin, positioning rod, tensioning mechanism, and support rod; The front of the connecting plate is provided with mounting hole I for installing positioning pins and positioning rods, the center of the connecting plate is provided with mounting hole II for installing tensioning mechanism, and the front of the connecting plate is provided with threaded hole I for connecting support rods. The tensioning mechanism includes an expansion sleeve, an expansion shaft, and a tie rod. The expansion sleeve includes an integrally connected bushing, flange, expansion cylinder, and elastic flap. The bushing is connected to the mounting hole II of the connecting plate through a transition fit and is fixedly connected to the connecting plate through the flange. The flange has three bolt holes I evenly distributed on it, and the connecting plate is provided with threaded holes II. The flange is fixedly connected to the connecting plate through screws I.

2. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 1, characterized in that: The elastic flaps consist of six flaps evenly distributed at the end of the expansion cylinder, with gaps between them. The inner cavity formed by the expansion cylinder and the elastic flaps is frustoconical in shape.

3. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 2, characterized in that: The tie rod passes through the bushing and the expansion cylinder, and is clearance-fitted with the bushing. One end of the tie rod is provided with a threaded hole, and is fixedly connected to the expansion shaft by screw II. The expansion shaft is a frustoconical shape with bolt hole II. When the tie rod moves to the left, it causes the expansion shaft to contact the inner side of the elastic flap and open the elastic flap.

4. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 2, characterized in that: Stress-relieving holes are provided at the connection between the root of the elastic valve and the expansion cylinder.

5. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 2, characterized in that: The lower outer wall of the elastic flap is thinned, and the maximum outer diameter of the outer circular surface of the elastic flap in its natural state is the same as the outer diameter of the expansion cylinder; the outer end of the elastic flap is chamfered.

6. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 1, characterized in that: Cleaning and treatment of the connection between the expansion cylinder, bushing, and flange.

7. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 1, characterized in that: One end of the positioning rod and the positioning pin is interference-fitted with the mounting hole I, and the other end of the positioning pin and the mounting hole I is provided with a positioning shaft, which is clearance-fitted with the mounting hole of the shell blank to be processed.

8. The machining and fixing fixture for the mounting surface of the automotive engine cooling water pump housing according to claim 1, characterized in that: One end of the support rod is provided with a screw, which is connected to a nut. The screw is connected to the threaded hole I of the connecting plate, and the other end of the support rod is in contact with the shell blank. Three bolt holes III are provided on the periphery of the connecting plate, and an inner stop is provided on the back of the connecting plate.

9. A machining and fixing method using a machining and fixing fixture for the mounting surface of an automotive engine cooling water pump housing as described in any one of claims 1 to 8, characterized in that: It includes the following steps: S1: The expansion sleeve, positioning pin, positioning rod, and support rod are installed on the connecting plate. The support rod is rotated to the deepest point of threaded hole I. The nut on the support rod is not tightened and does not contact the connecting plate. S2: The inner stop on the connecting plate is connected to the transition plate of the hydraulic CNC lathe and is fastened with three evenly distributed M10 bolts; S3: The tie rod passes through the expansion sleeve, and its left extended section is connected to the piston rod of the hydraulic cylinder of the hydraulic CNC lathe. The connection method is threaded connection. The right end of the tie rod is fixedly connected to the expansion shaft by screw II. The expansion shaft does not contact the expansion sleeve. S4: With the mounting surface of the housing blank facing outwards, that is, after the housing contacts the connecting plate, the mounting holes are far away from the connecting plate. There are a total of four mounting holes on the housing. Two of the mounting holes used for positioning are fitted into the positioning pins and positioning rods on the connecting plate, respectively. At the same time, the bearing hole of the housing blank enters the expansion sleeve. Push the housing inwards until the end face of the bearing hole of the housing hits the flange of the expansion sleeve and can no longer be pushed. S5: Rotate the two support rods outwards to adjust their heights, ensuring that the outer end face of the support rods is in effective contact with the two mounting holes of the housing. Tighten the support rods and connecting plate with nuts M12. S6: The piston rod of the hydraulic cylinder of the CNC lathe moves to the left, pulling the tie rod to the left. The expansion shaft fixed on the tie rod also moves to the left. The outer conical surface of the expansion shaft connects with the inner conical surface of the expansion sleeve. As the tie rod continues to move to the left, the expansion shaft opens up the six elastic petals on the expansion sleeve. The outer circular surface of the elastic petals is in close contact with the inner wall of the shaft hole of the housing blank, achieving precise positioning. S7: Start the lathe and begin machining. After machining is completed, the piston rod of the CNC lathe hydraulic cylinder moves to the right, pushing the pull rod to the right, and the expansion shaft also moves to the right. The expansion shaft separates from the expansion sleeve, the elastic flap of the expansion sleeve returns to its original position, and the expansion sleeve separates from the bearing hole of the housing. The workpiece is removed, and the machining of the next workpiece begins.

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