A clamp for machining a roots vacuum pump housing and a method of use

Abstract

The application relates to the technical field of clamps, and provides a clamp for machining a Roots vacuum pump shell and a use method, a work plate is fixedly connected to the top of a bottom plate through a supporting plate, a shell blank is located at the center of the work plate, the top of the work plate is connected with a clamping positioning mechanism, a pre-positioning mechanism, a lifting positioning mechanism and a hooking positioning mechanism; the clamping positioning mechanism comprises a first positioning block and a first telescopic piece which is oppositely arranged with the first positioning block; the lifting positioning mechanism comprises a plurality of guide columns which penetrate through the work plate, and the top of the guide column is connected with a third positioning block; the hooking positioning mechanism comprises a hook body which is used for hooking the inner cavity of the shell blank, and the hook body is slidably arranged on the work plate through a sliding assembly. The scheme is suitable for the irregular shape of the Roots vacuum pump shell, and the forming process of the shell is simply and conveniently realized through multidirectional positioning and clamping.

Description

Technical Field

[0001] This invention relates to the field of fixture technology, specifically to a fixture for machining the housing of a Roots vacuum pump and a method for using it. Background Technology

[0002] A Roots vacuum pump is a commonly used vacuum pump, also known as a Roots blower or Roots blower. It uses two impellers that rotate synchronously to create a vacuum by continuously drawing in and expelling gas.

[0003] To accommodate internal components such as the impeller, the casing of a Roots vacuum pump has a complex structure with an uneven and irregular surface. Machining holes or surfaces requires high precision, especially given the irregular shape of the casing. Appropriate fixtures are needed to ensure accurate positioning and clamping. Furthermore, due to the pump's size and structural limitations, the design space for these fixtures is limited, necessitating efficient use of the available space to achieve reliable clamping. Therefore, there is an urgent need for a fixture for the Roots vacuum pump casing that is simple in structure, easy to operate, and ensures compliance with process requirements. Summary of the Invention

[0004] To address the problems existing in the background technology, this invention proposes a fixture and method for processing the housing of a Roots vacuum pump. It adapts to the irregular shape of the Roots vacuum pump housing, provides multi-directional positioning and clamping, achieves precise positioning of the housing blank, improves processing accuracy, and ensures the forming process of the housing.

[0005] To achieve the above objectives, the present invention adopts the following solution:

[0006] A fixture for processing the housing of a Roots vacuum pump includes a base plate and a housing blank. The housing blank has a positioning groove. A working plate is fixed to the top of the base plate through a support plate. The housing blank is located at the center of the working plate. A clamping positioning mechanism and a pre-positioning mechanism are fixed on the upper surface of the working plate. A lifting positioning mechanism and a hooking positioning mechanism are also connected to the working plate.

[0007] The clamping and positioning mechanism is provided in multiple ways, and the multiple clamping and positioning mechanisms are respectively arranged on any two adjacent sides. The clamping and positioning mechanism includes a first positioning block and a first telescopic member arranged opposite to the first positioning block. The housing blank is located between the first positioning block and the first telescopic member.

[0008] The hooking and positioning mechanism includes a hook body that hooks into the positioning groove, and the hook body is slidably mounted on the work plate via a sliding component.

[0009] The pre-positioning mechanism includes a second positioning block and a second telescopic member. The second positioning block is located below the flat surfaces at both ends of the bottom of the housing blank, and at least one second telescopic member is provided on the side of the housing blank where the first telescopic member is provided.

[0010] The lifting and positioning mechanism includes multiple guide pillars extending through the upper part of the working plate and a second hydraulic cylinder. The top of the guide pillar is connected to a third positioning block for pressing against the flat surfaces at both ends of the bottom of the shell blank. The bottom of the guide pillar is connected to a clamping hydraulic cylinder. The multiple guide pillars are connected by a connecting plate located below the working plate. The connecting plate is vertically connected to the second hydraulic cylinder.

[0011] Furthermore, the first telescopic component includes a top shaft, which is telescopically connected to a first hydraulic cylinder. A cylinder plate is fixedly mounted at the bottom of the first hydraulic cylinder, and both the cylinder plate and the first positioning block are fixedly mounted on the working plate.

[0012] Furthermore, the second telescopic component includes a guide seat, on which a cavity is formed by the inward indentation of the end face facing the housing blank. A top block is slidably connected to the cavity. One end of the top block extends out of the cavity, and the other end of the top block is threaded with a screw. The end of the screw away from the top block passes through the cavity and extends out of the guide seat. A movable cavity for the top block to move is provided in the cavity. A countersunk hole is provided in the indentation of the end face of the top block near the movable cavity. A compression spring is fitted on the part of the screw located in the movable cavity and the countersunk hole. A plug is provided on the end of the screw extending out of the guide seat.

[0013] Furthermore, multiple second positioning blocks are provided, and these multiple second positioning blocks are used for positioning the positioning groove and the hook body.

[0014] Furthermore, the clamping cylinder and the second cylinder are fixed on the base plate, and the working plate is provided with holes corresponding to the number and position of the guide posts. Guide sleeves are fixed in the holes and are sleeved on the guide posts.

[0015] Furthermore, at least two hooking and positioning mechanisms are provided, and the two hooking and positioning mechanisms are arranged diagonally with the center of the shell blank as the center.

[0016] Furthermore, the sliding assembly includes a guide plate fixed on the working plate, a guide groove in the guide plate, a sliding hole penetrating the working plate at the bottom of the guide groove, a connecting rod that slides in the sliding hole and engages with the guide groove, the top end of the connecting rod being connected to the hook body, and the bottom end of the connecting rod passing through the sliding hole and connected to a third hydraulic cylinder via a piston rod, the third hydraulic cylinder being fixed on the bottom surface of the working plate.

[0017] A method for using a fixture for machining a Roots vacuum pump housing includes the following steps:

[0018] Step 1: Place the shell blank on the work plate, so that the second positioning block is located below the flat surfaces at both ends of the bottom of the shell blank; the second telescopic component is compressed and moves backward, cooperating with the first positioning block to make the second telescopic component press against the side wall of the shell blank, thereby achieving the pre-positioning of the shell blank;

[0019] Step 2: The hook body slides through the sliding component until it contacts the side wall of the positioning groove;

[0020] Step 3: The second cylinder drives the connecting plate to move upward, which in turn drives the guide post to move upward. The guide post drives the third positioning block to lift the shell blank upward, the positioning groove moves upward, and the hook catches the positioning groove to achieve the tight positioning of the shell blank.

[0021] Step 4: Activate the clamping cylinder to clamp the guide column to fix the position of the lifting and positioning mechanism, thereby achieving vertical positioning of the housing blank;

[0022] Step 5: Extend and fix the first telescopic component, while the first positioning block cooperates, and the first telescopic component presses against the side wall of the shell blank to achieve horizontal positioning of the shell blank.

[0023] The beneficial effects of this invention are as follows: This solution achieves precise positioning of the shell blank by setting multiple mechanisms to position and clamp the shell blank, thereby improving processing accuracy and ensuring the forming process of the shell: the pre-positioning mechanism achieves pre-positioning of the shell blank from the bottom and side to prevent the shell blank from moving; the clamping and positioning mechanism is used to clamp the edges of the shell blank around its perimeter; the lifting and positioning mechanism achieves clamping of the bottom of the blank by moving upward; and the hooking and positioning mechanism achieves hooking of the positioning groove of the shell blank through the sliding component, further positioning and fixing the shell blank. Therefore, this fixture adopts multi-directional positioning and clamping, which is simple to position and easy to operate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the clamp of the present invention;

[0025] Figure 2 This is a schematic diagram of the fixture structure in the working state of the present invention;

[0026] Figure 3 This is a side view of the fixture of the present invention.

[0027] Figure 4 This is a cross-sectional view of the fixture of the present invention.

[0028] Figure 5 This is a cross-sectional view of the second telescopic component of the clamp of the present invention;

[0029] Figure 6 This is a schematic diagram of the first telescopic component of the clamp of the present invention;

[0030] Figure 7 This is a schematic diagram of the sliding component structure of the clamp of the present invention.

[0031] Labels in the diagram: 1. First positioning block; 2. First telescopic component; 201. Top shaft; 202. First hydraulic cylinder; 3. Second positioning block; 203. Hydraulic cylinder plate; 4. Second telescopic component; 401. Guide seat; 402. Top block; 403. Compression spring; 404. Screw; 405. Movable cavity; 406. Countersunk hole; 5. Sliding assembly; 501. Guide plate; 502. Guide groove; 503. Sliding hole; 504. Connecting rod; 505. Hook body; 506. Third hydraulic cylinder; 6. Third positioning block; 7. Guide post; 8. Clamping hydraulic cylinder; 9. Connecting plate; 10. Base plate; 11. Shell blank; 12. Support plate; 13. Working plate; 14. Second hydraulic cylinder; 15. Guide sleeve; 16. Positioning groove. Detailed Implementation

[0032] To make the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the given embodiments are merely one implementation method and do not represent all embodiments.

[0033] Example 1

[0034] Combination Figures 1-7 This embodiment provides a fixture for processing the housing of a Roots vacuum pump, including a base plate 10 and a housing blank 11. The housing blank 11 is provided with a positioning groove 16. A working plate 13 is fixed to the top of the base plate 10 through a support plate 12. The housing blank 11 is located at the center of the working plate 13. A clamping positioning mechanism and a pre-positioning mechanism are fixed on the upper surface of the working plate 13. A lifting positioning mechanism and a hooking positioning mechanism are also connected to the working plate 13.

[0035] Multiple clamping and positioning mechanisms are provided, and the multiple clamping and positioning mechanisms are respectively arranged on any two adjacent sides. Each clamping and positioning mechanism includes a first positioning block 1 and a first telescopic member 2 arranged opposite to the first positioning block 1. The shell blank 11 is located between the first positioning block 1 and the first telescopic member 2. The hooking and positioning mechanism includes a hook body 505 that hooks into the positioning groove 16. The hook body 505 is slidably arranged on the working plate 13 through the sliding component 5.

[0036] The pre-positioning mechanism includes a second positioning block 3 and a second telescopic member 4. The second positioning block 3 is located below the flat surfaces at both ends of the bottom of the shell blank 11, and at least one second telescopic member 4 is provided on the side of the shell blank 11 where the first telescopic member 2 is provided.

[0037] The lifting and positioning mechanism includes multiple guide posts 7 extending through the upper part of the working plate 13 and a second hydraulic cylinder 14. The top of the guide post 7 is connected to a third positioning block 6 for pressing against the flat surfaces at both ends of the bottom of the shell blank 11. The bottom of the guide post 7 is connected to a clamping hydraulic cylinder 8. The multiple guide posts 7 are connected by a connecting plate 9 located below the working plate 13. The connecting plate 9 is vertically and vertically connected to the second hydraulic cylinder 14.

[0038] In this embodiment, the shell blank 11 is placed at the center of the working plate 13. Multiple mechanisms are set to position and clamp the shell blank 11 to achieve the shell forming process: the pre-positioning mechanism realizes the pre-positioning of the shell blank 11 from the bottom and the side to prevent the shell blank 11 from moving; the clamping positioning mechanism is used to clamp the edges of the shell blank 11 around; the lifting positioning mechanism realizes the bottom of the blank by moving upward; and the hooking positioning mechanism realizes the hooking of the positioning groove 16 of the shell blank 11 through the sliding component 5, further positioning and fixing the shell blank 11.

[0039] The first telescopic component 2 includes a top shaft 201, which is telescopically connected to a first hydraulic cylinder 202. A cylinder plate 203 is fixedly mounted at the bottom of the first hydraulic cylinder 202. Both the cylinder plate 203 and the first positioning block 1 are fixedly mounted on the working plate 13. The first positioning block 1 serves to initially position the second telescopic component 4 and to tighten the first telescopic component 2. The telescopic movement of the first hydraulic cylinder 202 drives the top shaft 201 to move, thereby clamping and releasing the shell blank 11. It should be understood that the length of the top shaft 201 can be selected according to actual needs, with the principle of tightening the shell blank 11.

[0040] Preferably, each of the adjacent sides of the shell blank 11 is provided with two clamping and positioning mechanisms, which are located at both ends of the shell blank 11, thus improving the stability of the horizontal positioning of the shell blank 11. Actual process operation shows that providing one second telescopic member 4 on each adjacent side of the shell blank 11 is sufficient to meet the process requirements. Preferably, the second telescopic member 4 is positioned at the center of one side of the shell blank 11, that is, at the center of the two clamping and positioning mechanisms on the same side of the shell blank 11, which is more conducive to pre-positioning. The second telescopic member 4 includes a guide seat 401. The guide seat 401 has a cavity formed by a recess in its end face facing the housing blank 11. A top block 402 is slidably connected to the cavity. One end of the top block 402 extends out of the cavity, and the other end is connected to a screw 404. The end of the screw 404 away from the top block 402 passes through the cavity and extends out of the guide seat 401. A movable cavity 405 is provided within the cavity for the top block 402 to move. A countersunk hole 406 is recessed in the end face of the top block 402 near the movable cavity 405. A compression spring 403 is provided on the portion of the screw 404 located within the movable cavity 405 and the countersunk hole 406. A plug is provided on the end of the screw 404 extending out of the guide seat 401. The size of the plug must be larger than the size of the hole through which the screw 404 passes through the guide seat 401 to prevent the screw 404 from being pulled out of the cavity by the top block 402. The top block 402 can move axially along the cavity. During positioning, the top block 402 compresses the spring 403 to pre-position the side wall of the shell blank 11. The screw 404 can restrict the top block 402 to prevent it from being ejected from the cavity when the shell is removed. It should be noted that the first telescopic member 2 can be directly fixed to the working plate 13, or it can be fixed to the working plate 13 via a base. The choice between the two methods depends on the space of the working plate 13. If there is enough space, a base can be used; otherwise, it can be directly fixed.

[0041] Specifically, multiple second positioning blocks 3 are provided, and these multiple second positioning blocks 3 are used for positioning the positioning groove 16 and the hook 505. When the second positioning blocks 3 are located below the flat surfaces at both ends of the bottom of the shell blank 11, the positions of the positioning groove 16 and the hook 505 correspond. During the positioning process, moving the hook 505 and the positioning groove 16 can quickly achieve the hook 505 hooking the positioning groove 16. Preferably, in this embodiment, four second positioning blocks 3 are provided, evenly distributed near the four corners of the shell blank 11.

[0042] Specifically, the clamping cylinder 8 and the second cylinder 14 are fixed on the base plate 10. The working plate 13 has holes corresponding to the number and position of the guide posts 7, and guide sleeves 15 are fixed in the holes, which are fitted onto the guide posts 7. The guide sleeves 15 facilitate the sliding of the guide posts 7. By extending and retracting the second cylinder 14, the connecting plate 9 is moved, and the connecting plate 9 causes the guide posts 7 and the third positioning block 6 to slide up and down within the guide sleeve 15, thereby enabling the third positioning block 6 to lift the shell blank 11 upward. After the second cylinder 14 is activated, the clamping cylinder 8 is activated, clamping the guide posts 7 and preventing them from moving downward. As a preferred embodiment, four guide posts 7 are provided, and correspondingly, four third positioning blocks 6 are provided, distributed at the four corners of the shell blank 11.

[0043] Specifically, at least two hooking and positioning mechanisms are provided, and the two hooking and positioning mechanisms are arranged diagonally with the center of the shell blank 11 as the center. The sliding assembly 5 includes a guide plate 501 fixed on the working plate 13. The guide plate 501 has a guide groove 502. The bottom of the guide groove 502 has a sliding hole 503 that penetrates the working plate 13. The sliding hole 503 has a connecting rod 504 that slides with the guide groove 502. The top end of the connecting rod 504 is connected to the hook body 505. The bottom end of the connecting rod 504 passes through the sliding hole 503 and is connected to a third hydraulic cylinder 506 through a piston rod. The third hydraulic cylinder 506 is fixed on the bottom surface of the working plate 13. By moving the third hydraulic cylinder 506, the connecting rod 504 is driven to move, thereby realizing that the connecting rod 504 drives the hook body 505 to slide in the guide groove 502, so that the hook body 505 can hook the positioning groove 16 of the shell blank 11.

[0044] Example 2

[0045] This invention also provides a method for using a fixture for machining the housing of a Roots vacuum pump, comprising the following steps:

[0046] Step 1: Place the shell blank 11 on the working plate 13, so that the second positioning block 3 is located below the flat surfaces at both ends of the bottom of the shell blank 11, thus ensuring that the positioning groove 16 and the hook body 505 are in corresponding positions; the top block 402 is compressed backward by the reverse force of the shell blank 11 and cooperates with the first positioning block 1 to make the second telescopic member 4 press against the side wall of the shell blank 11, thereby realizing the pre-positioning of the shell blank 11 at the bottom and side walls.

[0047] Step 2: Start the third hydraulic cylinder 506 to move the connecting rod 504, thereby enabling the connecting rod 504 to drive the hook body 505 to slide in the guide groove 502 until the hook body 505 contacts the side wall of the positioning groove 16.

[0048] Step 3: The second oil cylinder 14 drives the connecting plate 9 to move upward, which in turn drives the guide post 7 to move upward. The guide post 7 drives the third positioning block 6 to lift the shell blank 11 upward. At this time, the positioning groove 16 of the shell blank 11 moves upward, and the hook 505 slides to hook the positioning groove 16, thereby achieving the hooking and positioning of the shell blank 11.

[0049] Step 4: Activate the clamping cylinder 8 to clamp the guide column 7 to fix the position of the lifting and positioning mechanism, and then fix the position of the third positioning block 6 to achieve the vertical positioning of the shell blank 11.

[0050] Step 5: Start the first hydraulic cylinder 202 to drive the top shaft 201 to extend. At the same time, the first positioning block 1 cooperates, and the first hydraulic cylinder 202 presses against the side wall of the shell blank 11 to achieve horizontal positioning of the shell blank 11.

[0051] The specific embodiments of the present invention have been described in detail above with reference to the figures, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for using a fixture for machining a Roots vacuum pump housing, characterized in that: The fixture includes a base plate (10) and a shell blank (11). The shell blank (11) is provided with a positioning groove (16). The fixture is characterized in that: a working plate (13) is fixedly connected to the top of the base plate (10) through a support plate (12). The shell blank (11) is located at the center of the working plate (13). A clamping positioning mechanism and a pre-positioning mechanism are fixed on the upper surface of the working plate (13). A lifting positioning mechanism and a hooking positioning mechanism are also connected to the working plate (13). The clamping and positioning mechanism is provided in multiple ways, and the multiple clamping and positioning mechanisms are respectively provided on any two adjacent sides. The clamping and positioning mechanism includes a first positioning block (1) and a first telescopic member (2) provided opposite to the first positioning block (1). The shell blank (11) is located between the first positioning block (1) and the first telescopic member (2). The hooking and positioning mechanism includes a hook body (505) that hooks into the positioning groove (16), and the hook body (505) is slidably mounted on the working plate (13) via the sliding component (5). The pre-positioning mechanism includes a second positioning block (3) and a second telescopic member (4). The second positioning block (3) is located below the flat surfaces at both ends of the bottom of the shell blank (11). At least one second telescopic member (4) is provided on the side of the shell blank (11) where the first telescopic member (2) is provided. The lifting and positioning mechanism includes multiple guide columns (7) extending through the upper part of the working plate (13) and a second oil cylinder (14). The top of the guide column (7) is connected to a third positioning block (6) for pressing against the flat surfaces at both ends of the bottom of the shell blank (11). The bottom of the guide column (7) is connected to a clamping oil cylinder (8). The multiple guide columns (7) are connected by a connecting plate (9) located below the working plate (13). The connecting plate (9) is vertically connected to the second oil cylinder (14). The method of using the fixture includes the following steps: Step 1: Place the shell blank (11) on the working plate (13) so that the second positioning block (3) is located below the flat surfaces at both ends of the bottom of the shell blank (11); the second telescopic member (4) is compressed and moves backward, and cooperates with the first positioning block (1) to realize that the second telescopic member (4) presses against the side wall of the shell blank (11), thereby realizing the pre-positioning of the shell blank (11); Step 2: The hook (505) slides through the sliding component (5) until it contacts the side wall of the positioning groove (16); Step 3: The second cylinder (14) drives the connecting plate (9) to move upward, which in turn drives the guide post (7) to move upward. The guide post (7) drives the third positioning block (6) to lift the shell blank (11) upward. The positioning groove (16) moves upward, and the hook (505) hooks the positioning groove (16) to achieve the hooking and positioning of the shell blank (11). Step 4: Start the clamping cylinder (8) to clamp the guide column (7) to fix the position of the lifting and positioning mechanism and realize the vertical positioning of the shell blank (11); Step 5: Extend and fix the first telescopic component (2), while the first positioning block (1) cooperates, and the first telescopic component (2) presses against the side wall of the shell blank (11) to achieve the horizontal positioning of the shell blank (11).

2. The method of using a jig for machining a Roots vacuum pump housing according to claim 1, characterized in that: The first telescopic component (2) includes a top shaft (201), which is telescopically connected to a first oil cylinder (202). A cylinder plate (203) is fixedly provided at the bottom of the first oil cylinder (202). The cylinder plate (203) and the first positioning block (1) are both fixedly provided on the working plate (13).

3. The method of using a jig for machining a Roots vacuum pump housing according to claim 1, characterized in that: The second telescopic component (4) includes a guide seat (401). The guide seat (401) has a cavity formed by the indentation of the end face facing the housing blank (11). A top block (402) is slidably connected in the cavity. One end of the top block (402) extends out of the cavity. The other end of the top block (402) is threaded with a screw (404). The end of the screw (404) away from the top block (402) passes through the cavity and extends out of the guide seat (401). The cavity has a movable cavity (405) for the top block (402) to move. The end face of the top block (402) near the movable cavity (405) is recessed with a countersunk hole (406). The part of the screw (404) located in the movable cavity (405) and the countersunk hole (406) is fitted with a compression spring (403). The end of the screw (404) extending out of the guide seat (401) is provided with a plug.

4. The method of using a jig for machining a Roots vacuum pump housing according to claim 1, characterized in that: Multiple second positioning blocks (3) are provided, and multiple second positioning blocks (3) are used for positioning the positioning groove (16) and the hook body (505).

5. The method of using a jig for machining a Roots vacuum pump housing according to claim 1, characterized in that: The clamping cylinder (8) and the second cylinder (14) are fixed on the base plate (10). The working plate (13) has holes corresponding to the number and position of the guide post (7). A guide sleeve (15) is fixed in the hole and is sleeved on the guide post (7).

6. The method of using a jig for machining a Roots vacuum pump housing according to claim 1, characterized in that: At least two hooking and positioning mechanisms are provided, and the two hooking and positioning mechanisms are arranged diagonally with the center of the shell blank (11) as the center.

7. A method for using a jig for machining a Roots vacuum pump housing according to claim 1 or 6, characterized in that: The sliding assembly (5) includes a guide plate (501) fixed on the working plate (13). The guide plate (501) has a guide groove (502) inside. The bottom of the guide groove (502) has a sliding hole (503) that penetrates the working plate (13). The sliding hole (503) has a connecting rod (504) that slides with the guide groove (502). The top end of the connecting rod (504) is connected to the hook body (505). The bottom end of the connecting rod (504) passes through the sliding hole (503) and is connected to a third oil cylinder (506) through a piston rod. The third oil cylinder (506) is fixed on the bottom surface of the working plate (13).

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