A new process for machining support-type parts and its special fixture

Abstract

This invention discloses a novel machining process for support-type parts and its dedicated fixture, comprising the following steps: Step 1: Heat treatment of the support blank before machining to relieve stress and eliminate blank stress; Step 2: Machining the base of the support, controlling the outer diameter of the support, and machining a fourth bolt hole on the large surface of the base for subsequent clamping; Step 3: Installing the support onto a machine tool with a dedicated fixture, rough machining the arc surface, leaving a first allowance for the arc, and performing stress relief treatment to eliminate machining stress; Step 4: Single-sided grinding of the large end face of the support, mainly to remove deformation caused by stress relief, achieving a flatness within 0.01mm; Step 5: Installing the support onto a machine tool with a dedicated fixture, and finishing machining the remaining dimensions of the support; This invention can reduce workpiece clamping deformation and material stress deformation during continuous machining.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically a new process for machining support-type parts and its dedicated fixture. Background Technology

[0002] The function of a hydraulic pump is to convert the mechanical energy of a prime mover into pressure energy, thus providing power to the engine. The hydraulic pump's support is typically integrated with a swashplate bracket within the pump. The support consists of a base and an arc track, which are an integrated structure. Normally, machining the arc track requires custom-made cutting tools, resulting in high costs and low efficiency. During operation, the support's arc track and the swashplate bracket experience relative movement. However, due to the product's structural limitations, the support is susceptible to deformation during actual machining due to material and processing stresses. In actual operation, the relative movement between the support's arc track and the swashplate bracket can lead to significant friction at the contact surfaces, affecting the pump's reliability and lifespan. Summary of the Invention

[0003] In order to address the difficulties and shortcomings of the prior art, the present invention aims to provide a new process method and equipment specifically for processing supports, which can effectively solve the problem of deformation of supports caused by material stress and processing stress, and reduce processing and manufacturing costs.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A new process for machining support-type parts includes the following steps:

[0006] Step 1: Heat treatment is performed on the support blank before machining to relieve stress and eliminate stress in the blank;

[0007] Step 2: The support undergoes a base machining process, controlling the outer diameter of the support and machining the fourth bolt hole on the large surface of the base for subsequent clamping.

[0008] Step 3: Install the support onto a machine tool with a special fixture, perform rough machining on the arc surface, leaving a first allowance for the arc of the support, and perform stress relief treatment to eliminate machining stress;

[0009] Step 4: Perform a single-sided grinding process on the large end face of the support, mainly to remove the deformation caused by stress, and achieve a flatness within 0.01mm.

[0010] Step 5: Install the support onto a machine tool equipped with a special fixture, and perform finishing machining on the remaining dimensions of the support;

[0011] The steps for installing the support onto a machine tool with a special fixture are as follows: Position the support along the inner wall of the second locating pin and the second locating sleeve onto the end face of the connecting plate boss. Secure the support to the connecting plate using the fourth bolt. Pick up the connecting assembly and install it onto the front or rear port of the fixture body along the inner wall of the first locating pin, the front or rear first locating sleeve, and the stud. Secure the connecting assembly to the fixture body using the pressure plate and threaded sleeve. Install the connecting assembly on both the front and rear ports of the fixture body. The arc surfaces of the two supports in the two connecting assemblies are two segments of the same full circle, with the center of the circle coinciding with the rotation center of the machine tool.

[0012] The bearing blank is subjected to stress relief treatment at 560 degrees before processing; the tolerance zone for controlling the outer diameter of the bearing reaches H7 grade; the first allowance is 1±0.5mm.

[0013] During the machining process, an inside diameter gauge is used to measure the diameter and roundness of the arc surface. After the machining is qualified, the tooling and parts are disassembled in sequence. Four connecting components are prepared during on-site machining to achieve continuous and uninterrupted machining production.

[0014] A special fixture for a new process of machining support-type parts includes a base assembly and a connecting assembly. The base assembly includes a fixture body, a first positioning sleeve, and a flange.

[0015] The clamp body is rectangular. The clamp body has through holes along its vertical centerline to form an upper port and a lower port. The clamp body also has through holes along its front-back centerline to form a front port and a rear port. The front and rear faces of the clamp body are provided with studs.

[0016] The first positioning sleeve is divided into a front first positioning sleeve and a rear first positioning sleeve, with the front port having the front first positioning sleeve and the rear port having the rear first positioning sleeve.

[0017] The lower port is connected to the flange, and the flange is installed on the machine tool chuck so that the center line of the fixture in the vertical direction coincides with the rotation center of the machine tool.

[0018] The connecting assembly includes a connecting plate and a second positioning sleeve;

[0019] The connecting plate is provided with a boss, and the second positioning sleeve is provided on the boss. The second positioning sleeve can be nested inside the first positioning sleeve. The connecting plate is provided with a guide hole.

[0020] The boss is provided with a second positioning pin and a fourth bolt;

[0021] The second positioning sleeve is fitted into the front or rear first positioning sleeve, and the guide hole is aligned with the stud and inserted. The threaded sleeve and stud are used to press the connecting plate onto the front or rear port.

[0022] The second locating pin is mounted on the boss of the connecting plate via a locating pin seat.

[0023] At least two fourth bolts are provided on the boss;

[0024] The front first positioning sleeve, the rear first positioning sleeve and the clamp body are connected by the first bolt;

[0025] The lower port is connected to the flange by a second bolt;

[0026] The second positioning sleeve is mounted on the boss by a third bolt.

[0027] A pressure plate is provided between the threaded sleeve and the clamping body. The pressure plate is circular and has an open groove.

[0028] The front first positioning sleeve, the rear first positioning sleeve, and the second positioning sleeve are heat-treated to improve hardness and wear resistance.

[0029] A first positioning pin is provided between the front first positioning sleeve or the rear first positioning sleeve and the clamping body;

[0030] The first positioning pin extends out of the front or rear first positioning sleeve, and the connecting plate is provided with a positioning pin hole corresponding to the first positioning pin.

[0031] A third positioning pin is provided between the second positioning sleeve and the connecting plate.

[0032] The clamp body is machined into a hollow structure.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] This invention reduces workpiece clamping deformation and material stress deformation during continuous processing. Utilizing conventional measuring tools for on-site inspection, and with a processing equipment capable of processing two pieces at a time, it achieves rapid and direct inspection, increasing production efficiency by 50%, reducing the investment cost of using high-end inspection equipment, minimizing wasted measurement waiting time, and significantly improving economic efficiency and scalability. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the connecting plate of a special fixture for a new process of machining support-type parts according to the present invention.

[0036] Figure 2 This is a schematic diagram of the connection assembly of a special fixture for a new process of machining support-type parts according to the present invention.

[0037] Figure 3 This is a schematic diagram of the pressure plate of a special fixture for a new process of machining support-type parts according to the present invention.

[0038] Figure 4 This is a schematic diagram of the structure of a support-type part processed by a new process according to the present invention.

[0039] Figure 5 This is a schematic diagram of a special fixture for clamping a support in a new process for machining support-type parts according to the present invention;

[0040] In the diagram: 1. Clamp body; 2. First positioning sleeve; 3. Threaded sleeve; 4. Flange; 5. First bolt; 6. Second bolt; 7. First positioning pin; 8. Stud; 9. Second positioning sleeve; 10. Second positioning pin; 11. Connecting plate; 12. Third positioning pin; 13. Third bolt; 14. Support; 1401. Fourth bolt hole; 1402. Large end face of support; 1403. Arc surface; 15. Positioning pin seat; 16. Pressure plate; 17. Fourth bolt. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Please see Figures 1 to 5 The present invention discloses a new process for machining support-type parts and a special fixture thereof, including the following steps:

[0043] Step 1: Before machining the blank of support 14, perform stress relief treatment at 560 degrees to eliminate the stress in the blank.

[0044] Step 2: The support 14 is processed into a base, and the outer circle dimension of the support is controlled to reach the H7 grade tolerance. The fourth bolt hole 1401 is machined on the large surface of the base for subsequent clamping.

[0045] Step 3: Install the support 14 onto a machine tool with a special fixture, perform rough machining on the arc surface 1403, leaving an allowance of 1±0.5mm on the arc surface 1403 of the support 14, and perform stress relief treatment to eliminate machining stress.

[0046] Step 4: Perform a single-sided grinding process on the large end face 1402 of the support, mainly to remove the deformation caused by stress, and achieve a flatness within 0.01mm.

[0047] Step 5: Install the support 14 onto a machine tool equipped with a special fixture, and perform finishing on the remaining dimensions of the support 14;

[0048] The steps for installing the support 14 onto the machine tool with a special fixture are as follows: Place the support 14 on the boss end face of the connecting plate 11 along the inner wall of the second locating pin 10 and the second locating sleeve 9. Use the fourth bolt 17 to fix the support 14 to the connecting plate 11. Pick up the connecting assembly and install it onto the front or rear port of the fixture body 1 along the inner wall of the first locating pin 7, the front or rear first locating sleeve, and the stud. Use the pressure plate 16 and the threaded sleeve 3 to fix the connecting assembly to the fixture body 1. Install the connecting assembly on both the front and rear ports of the fixture body. The arc surfaces 1403 of the two supports 14 in the two connecting assemblies are two segments of the same full circle, with the center of the circle coinciding with the rotation center of the machine tool. Machining is performed using a conventional lathe tool.

[0049] During the machining process, an inner diameter gauge can be used to measure the diameter and roundness of the arc surface. After the machining is qualified, the tooling and parts can be disassembled in sequence. Two sets of tooling can be prepared on-site to achieve continuous and uninterrupted machining production. Example 1

[0050] Please see Figures 1 to 5 The special fixture includes a base assembly and a connecting assembly. The base assembly includes a fixture body 1, a first positioning sleeve 2, and a flange 4.

[0051] The clamp body 1 is a rectangular body. The clamp body has through holes along its vertical centerline to form an upper port and a lower port. The clamp body also has through holes along its front-back centerline to form a front port and a rear port. The first positioning sleeve 2 is divided into a front first positioning sleeve and a rear first positioning sleeve. The front port has a front first positioning sleeve and the rear port has a rear first positioning sleeve. The front first positioning sleeve and the rear first positioning sleeve are connected to the clamp body using a first bolt 5. The lower port is connected to the flange 4 using a second bolt.

[0052] The flange 4 is installed on the machine tool chuck, so that the center line of the fixture body 1 in the vertical direction coincides with the rotation center of the machine tool.

[0053] The clamp body 1 has studs 8 on its front and rear faces.

[0054] The connecting assembly includes a connecting plate 11 and a second positioning sleeve 9; the connecting plate 11 is provided with a boss, and the second positioning sleeve 9 is mounted on the boss by a third bolt, and the second positioning sleeve 9 can be nested inside the first positioning sleeve 2; the connecting plate 11 is provided with a guide hole; a positioning pin seat 15 is provided on the boss, and a second positioning pin 10 is provided on the positioning pin seat 15; the second positioning pin 10 and the inner hole guide support 14 of the second positioning sleeve 9 sit on the boss, and the support 14 is fixedly connected to the connecting plate 11 by at least two fourth bolts.

[0055] When the connecting component is connected to the base component, the second positioning sleeve 9 is fitted into the front first positioning sleeve or the rear first positioning sleeve, the guide hole is aligned with the stud and inserted, and the threaded sleeve 3 and the pressure plate 16 are used to press the connecting plate 11 onto the front port or the rear port of the clamp body 1.

[0056] The pressure plate is disposed between the threaded sleeve 3 and the connecting plate 11. The pressure plate 16 is circular and has an open groove.

[0057] When both the front and rear ports of the fixture body 1 are equipped with connecting components, the two fixed supports 14 in the two connecting components are joined together to form a complete circle. The center of the two supports 14 coincides with the center line of the fixture body 1 in the vertical direction, that is, coincides with the rotation center of the machine tool. The machining is carried out using a conventional lathe tool. During the machining process, the diameter and roundness of the arc surface 1403 can be measured using an inner diameter gauge. Example 2

[0058] In Example 1, the first positioning sleeve 2 and the second positioning sleeve 9 wear against each other and are consumable parts. Therefore, this example is an improvement on Example 1. The front first positioning sleeve, the rear first positioning sleeve, and the second positioning sleeve are heat-treated to improve hardness and wear resistance.

[0059] A first positioning pin 7 is provided between the front first positioning sleeve or the rear first positioning sleeve and the clamping body 1, which facilitates the replacement of the front first positioning sleeve or the rear first positioning sleeve.

[0060] The first positioning pin 7 extends out of the front or rear first positioning sleeve, and the connecting plate 11 is provided with a positioning pin hole corresponding to the first positioning pin 7, so that the connecting plate 11 can be accurately installed on the front or rear face.

[0061] A third positioning pin 12 is provided between the second positioning sleeve 9 and the connecting plate 11 to facilitate the replacement of the second positioning sleeve.

[0062] The clamping body 1 is machined into a hollow structure to reduce weight while ensuring structural strength. This reduces centrifugal force during processing and helps stabilize the workpiece dimensions.

[0063] Specifically, the functions of each component in the special fixture:

[0064] The clamp body 1 is used to connect the flange 4 and the connecting plate 11.

[0065] The first positioning sleeve 2 is used to connect the clamp body 1 and the connecting plate 11. It is located at the center of the clamp body and is a wear-prone part. The main purpose of its separate design is to allow for timely replacement of the first positioning sleeve 2 after wear, thereby reducing costs.

[0066] Threaded sleeve 3 is used to fix the connecting plate. Its main function is to significantly improve the strength and wear resistance of the threaded connection; prevent the threads from loosening and stripping; and can be replaced and repaired separately, reducing costs.

[0067] Flange 4 is used to connect clamp body 1 and machine tool chuck. Flange 4 is made of cast iron and can be heat treated to improve surface hardness and enhance stability.

[0068] The first bolt 5 is used to connect the first positioning sleeve 2 and the clamping body 1.

[0069] The second bolt 6 is used to connect the flange 4 and the clamp 1.

[0070] The first positioning pin 7 is used to accurately install the first positioning sleeve 2 and to provide angular positioning for the connecting plate 11.

[0071] Stud 8 is used to connect the clamp body 1 and the connecting plate 11.

[0072] The second positioning sleeve 9 serves to provide positioning and guidance when the connecting component is installed onto the base component, and to provide positioning and guidance for the support 14 when it is installed.

[0073] The second locating pin 10 serves to position the support 14 at an angle.

[0074] The connecting plate 11 is used in conjunction with the clamping body 1. The end face of the connecting plate boss needs to be surface ground, and the flatness is required to be within 0.01mm.

[0075] The cylindrical pin 12 is used to accurately install the second positioning sleeve 9.

[0076] The third bolt 13 is used to connect the second positioning sleeve 9 and the connecting plate 11.

[0077] Support 14, the machined part of the present invention.

[0078] The positioning pin seat 15 is used to install the second positioning pin 10 onto the connecting plate 11.

[0079] The pressure plate 16 is used to press the connecting plate 11 and to facilitate its removal during disassembly.

[0080] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0081] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0082] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0083] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A new process for machining support-type parts, characterized in that, This processing technology uses a fixture for processing support-type parts. The fixture includes a base assembly and a connecting assembly. The base assembly includes a fixture body, a first positioning sleeve, and a flange. The fixture is rectangular. Through holes are provided along the center lines of the fixture in the vertical direction to form an upper port and a lower port. Through holes are provided along the center lines of the fixture in the front and rear directions to form a front port and a rear port. Studs are provided on the front and rear faces of the fixture. The lower port is connected to a flange, which is mounted on the machine tool chuck so that the center lines of the fixture in the vertical direction coincide with the rotation center of the machine tool. The first positioning sleeve is divided into a front first positioning sleeve and a rear first positioning sleeve, with the front port having a front first positioning sleeve and the rear port having a rear first positioning sleeve. A first positioning pin is provided between the front first positioning sleeve or the rear first positioning sleeve and the clamping body; The connecting assembly includes a connecting plate and a second positioning sleeve; the connecting plate is provided with a boss, the second positioning sleeve is provided on the boss, and the second positioning sleeve can be nested inside the first positioning sleeve; the connecting plate is provided with a guide hole; at least two fourth bolts are provided on the boss, and a second positioning pin is connected to the boss; The second positioning sleeve is fitted into the front or rear first positioning sleeve, and the guide hole is aligned with the stud and inserted. The threaded sleeve and the stud are used to press the connecting plate onto the front or rear port. A pressure plate is provided between the threaded sleeve and the clamping body. The pressure plate is circular and has an open groove. The processing technology includes the following steps: Step 1: Heat treatment is performed on the support blank before machining to relieve stress and eliminate stress in the blank; Step 2: The support undergoes a base machining process, controlling the outer diameter of the support and machining the fourth bolt hole on the large surface of the base for subsequent clamping. Step 3: Install the support onto the fixture, rough machine the arc surface, leaving a first allowance on the arc surface of the support, and perform stress relief treatment to eliminate machining stress; Step 4: Perform a single-sided grinding process on the large end face of the support to remove the deformation caused by stress, and achieve a flatness within 0.01mm; Step 5: Install the support onto the fixture and finish the remaining dimensions of the support; The steps for installing the support onto the fixture are as follows: Position the support along the inner wall of the second locating pin and the second locating sleeve onto the end face of the connecting plate boss, and use the fourth bolt to fix the support to the connecting plate; Pick up the connecting assembly and install it onto the front or rear port of the fixture body along the inner wall of the first locating pin, the front or rear first locating sleeve, and the stud; use the pressure plate and threaded sleeve to fix the connecting assembly to the fixture body. Install the connecting assembly on both the front and rear ports of the fixture body. The arc surfaces of the two supports in the two connecting assemblies are two segments of the same full circle, with the center of the circle coinciding with the rotation center of the machine tool.

2. The novel process for machining support-type parts according to claim 1, characterized in that, The second locating pin is mounted on the boss of the connecting plate via a locating pin seat.

3. A novel process for machining support-type parts according to claim 1, characterized in that, The front first positioning sleeve, the rear first positioning sleeve and the clamp body are connected by the first bolt; The lower port is connected to the flange by a second bolt; The second positioning sleeve is mounted on the boss by a third bolt.

4. A novel process for machining support-type parts according to claim 1, characterized in that, The front first positioning sleeve, the rear first positioning sleeve, and the second positioning sleeve are heat-treated to improve hardness and wear resistance.

5. A novel process for machining support-type parts according to claim 1, characterized in that, A first positioning pin is provided between the front first positioning sleeve or the rear first positioning sleeve and the clamping body; The first positioning pin extends out of the front or rear first positioning sleeve, and the connecting plate is provided with a positioning pin hole corresponding to the first positioning pin. A third positioning pin is provided between the second positioning sleeve and the connecting plate.

6. A novel process for machining support-type parts according to claim 1, characterized in that, The clamp body is machined into a hollow structure.

7. A novel process for machining support-type parts according to claim 1, characterized in that, The support blank is subjected to stress relief treatment at 560 degrees before processing. The tolerance zone of the outer circle dimension of the control support reaches grade H7; The first allowance is 1 ± 0.5 mm.

8. A novel process for machining support-type parts according to claim 7, characterized in that, During the machining process, an inside diameter gauge is used to measure the diameter and roundness of the arc surface. After the machining is qualified, the tooling and parts are disassembled in sequence. Four connecting components are prepared during on-site machining to achieve continuous and uninterrupted machining production.

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