Inner hole positioning device
The core shaft and ejector pin structure of the inner hole positioning device solves the problem of rapid positioning of parts with larger inner holes, realizing a simple and low-cost processing solution. It is suitable for positioning parts with inner hole sizes of φ300-φ500 and tolerances of ±0.1mm, thereby improving production efficiency.
Patent Information
- Application Number
- CN202422646010.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-10-31
AI Technical Summary
Existing technology cannot effectively position parts with larger inner hole sizes, especially parts with a diameter of 380±0.1mm. Mandrels or expansion sleeves cannot be used for clamping, which increases the difficulty of processing.
An inner hole positioning device is used, including a tooling base, a centering support, a vertically liftable core shaft, a screw, a push pin and a positioning slider. The positioning of the inner hole of the workpiece is achieved by lifting the core shaft and sliding the push pin horizontally. The compression spring and connecting screw are used to ensure that the push pin and the core shaft fit tightly, thereby achieving quick clamping.
It realizes the rapid positioning of parts with larger inner hole sizes, reduces the processing difficulty, improves production efficiency, and has simple structure, easy maintenance, low cost, and is suitable for the positioning needs of workpieces with different hole diameters.
Smart Images
Figure CN223394852U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of annular part inner hole positioning and clamping devices, and particularly relates to an inner hole positioning device. Background Art
[0002] With the rapid development of the automobile industry, the production efficiency of auto parts is becoming more and more important, and the competition among peers is becoming more and more fierce. The positioning of auto parts in processing is very important.
[0003] For example, the automotive component shown in Figure 1 is typically clamped using a mandrel and expansion sleeve to locate the inner hole of a part with moderate precision. However, this part has a large inner hole size of φ380±0.1mm and requires moderate precision. Due to structural limitations, mandrel or expansion sleeve clamping is not feasible. To address this, the following technical solution is proposed. Utility Model Content
[0004] The technical problem solved by the utility model is to provide an inner hole positioning device to solve the technical problem of fast clamping and positioning of parts with larger inner hole sizes.
[0005] The technical solution adopted by the utility model is as follows: an inner hole positioning device is provided with a tooling base plate, a centering support is fixedly installed on the tooling base plate; a pressure cover is installed on the top of the centering support; a core shaft that can be vertically lifted and lowered is concentrically installed on the inner side of the centering support; the top end of the core shaft is connected to the bottom end of the screw rod; the screw rod body is rotated to fit the center hole of the pressure cover; the top end of the screw rod is fixedly connected to the operating part; the screw rod is rotated to drive the core shaft to rise and fall; the bottom end of the core shaft body is formed with an outer conical surface, and the outer conical surface is tightly fitted with one end of a horizontally arranged ejector pin; the other end of the ejector pin is connected to a positioning slider through a connecting screw; the lifting core shaft is lifted and lowered by Its outer conical surface pushes the ejector pin to slide horizontally; the horizontally sliding ejector pin drives the positioning slider to slide horizontally in the slider support; the connecting screw is coaxially packaged with a compression spring; the restoring elastic force of the compression spring is used to make the ejector pin always fit tightly against the outer conical surface of the core shaft; the ejector pin, connecting screw, compression spring, positioning slider, and slider support are respectively provided in three groups, and the three groups of ejector pins, connecting screws, compression springs, positioning sliders, and slider supports are respectively evenly distributed along the radial direction of the centering support; the inner hole positioning of the workpiece is achieved by the outer arc positioning surface of the positioning slider that moves horizontally along the radial direction.
[0006] In the above technical solution, preferably: the operating part is a hand wheel or a handle, and rotating the hand wheel or the handle drives the screw to rotate.
[0007] In the above technical solution, preferably: the bottom end of the screw is rotatably connected to the inverted T-shaped slot formed on the top end of the core shaft through an inverted T-shaped structure, and the core shaft is driven to rise and fall vertically in the centering support through the rotating screw.
[0008] In the above technical solution, preferably: an inclined arc groove is formed on the inner end of the ejector pin; the inclined arc groove is closely fitted to the outer conical surface of the matching core shaft; the lifting outer conical surface of the core shaft drives the ejector pin to achieve horizontal displacement of the ejector pin.
[0009] In the above technical solution, preferably: the connecting screw rod is provided with external threads at both ends and a boss is provided in the middle, the external threads at both ends of the connecting screw rod are respectively fixed to the top pin and the internal threaded holes of the positioning slider; the middle part of the connecting screw rod body is screwed to fit and install the adjusting nut; a compression spring is installed on the outside of the adjusting nut.
[0010] In the above technical solution, as a further improvement of the present invention: a linear slide groove is formed on the top of the positioning slider; a positioning screw is vertically installed on the slider support; the positioning screw is inserted into the linear slide groove and displaced along the linear slide groove, and the positioning screw and the linear slide groove provide a linear guide for the linear displacement of the positioning slider.
[0011] In the above technical solution, preferably, the installation height of the ejector pin in the centering support is the same as the installation height of the positioning slider in the slider support.
[0012] In the above technical solution, as a further improvement of the present invention: it also includes a base, an inner hole positioning device is provided at the center of the upper end face of the base; a plurality of support blocks are provided radially around the inner hole positioning device; the support blocks are respectively equipped with pressure plates; the pressure plates are used to press the outer periphery of the workpiece after the inner hole is positioned.
[0013] In the above technical solution, as a further improvement of the present invention: the base is formed with a keyway and a pressure plate groove, and the keyway and the pressure plate groove are used for positioning and pressing the base on the machine tool table.
[0014] In the above technical solution, as a further improvement of the present invention: it also includes an angular positioning device; the angular positioning device is arranged beside the inner hole positioning device.
[0015] The advantages of this utility model compared with the prior art are:
[0016] 1. The utility model has a simple and practical structure, low manufacturing and maintenance costs, easy and quick operation, and can be disassembled and used repeatedly. It can mainly solve the problem of rapid positioning of inner holes with large inner hole sizes (φ300-φ500) and moderate tolerances (±0.1mm); it fills the gap in inner hole positioning processing during small and medium-sized batch processing of shell parts, and has strong promotional potential.
[0017] 2. The utility model only needs to replace the positioning slider for workpieces with different hole diameters. The positioning slider can quickly realize the inner hole positioning and clamping through its process control, and ensure concentricity to meet the positioning requirements.
[0018] 3. The utility model has a simple structure and is easy to maintain. From the production perspective, it reduces the processing difficulty, improves the production efficiency, and reduces the product processing cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1(a) is a front view of a workpiece to be processed;
[0020] Figure 1(b) is an AA cross-sectional view of the workpiece to be machined;
[0021] Figure 2 This is a schematic diagram of the longitudinal cross-section structure of the inner hole positioning device of the utility model;
[0022] Figure 3 This is a top view of the inner hole positioning device of the utility model;
[0023] Figure 4 This is a top view of the positioning slider of the utility model;
[0024] Figure 5 This is a longitudinal cross-sectional view of the positioning slider of the utility model;
[0025] Figure 6 This is the main view of the mandrel of the utility model;
[0026] Figure 7 For the core shaft Figure 6 Side view;
[0027] Figure 8 This is the front view of the top pin of the utility model;
[0028] Figure 9 This is a three-dimensional diagram of the top pin of the utility model;
[0029] Figure 10 This is a complete structural diagram of the utility model in use;
[0030] Figure 11 For this utility model Figure 10 Top view.
[0031] In the figure: 1-positioning slider, 1.1-external arc positioning surface, 1.2-linear slide, 2-slider support, 3-lift pin, 3.1-inclined arc groove, 4-centering support, 5-core shaft, 5.1-external conical surface, 5.2-inverted T-slot, 6-pressure cover, 7-handwheel, 8-compression spring, 9-adjusting nut, 10-connecting screw, 101-boss, 11-handle, 12-screw, 13-tooling base, 14-positioning screw, 15-base, 151-keyway and pressure plate groove, 16-inner hole positioning device, 17-support block, 18-pressure plate, 19-angular positioning device. DETAILED DESCRIPTION
[0032] The following will be combined with Figures 1-11 of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0033] An inner hole positioning device (such as Figure 2 As shown) there is a tooling base plate 13 in the shape of a disc, and the tooling base plate 13 is fixedly installed with the centering support 4 by interference fit, and the tooling base 13 is also fastened and fixedly installed with the slider support 2 described later.
[0034] A disc-shaped gland 6 is fixedly mounted on the top of the centering support 4 , and a core shaft 5 is provided inside the gland 6 .
[0035] A vertically movable core shaft 5 is concentrically mounted inside the centering support 4. The vertical movement of the core shaft 5 is ensured by the dimensional accuracy of the core shaft 5's fit with the inner hole of the centering support 4. Specifically, the core shaft 5 and the centering support 4 use a small clearance fit (H7 / h6), ensuring accuracy and stability when the core shaft 5 moves up and down.
[0036] The top end of the core shaft 5 is connected to the bottom end of the screw rod 12; the rod body of the screw rod 12 is screwed to fit the center hole of the pressure cover 6; the top end of the screw rod 12 is fixedly connected to the operating part; rotating the screw rod 12 drives the core shaft 5 to rise and fall.
[0037] In the above embodiment, preferably: (combined with Figure 6 、 Figure 7 (As shown) the bottom end of the screw rod 12 is rotatably connected to the inverted T-shaped slot 5.2 formed on the top end of the core shaft 5 through an inverted T-shaped structure, and the core shaft 5 is driven to rise and fall vertically in the centering support 4 by the rotating screw rod 12.
[0038] (like Figure 2 (As shown in the figure), the bottom end of the core shaft 5 is formed with an outer conical surface 5.1, and the outer conical surface 5.1 fits tightly and tightly with one end of the horizontally arranged ejector pin 3 without any gap; the other end of the ejector pin 3 is connected to the positioning slider 1 through a connecting screw 10; the lifting core shaft 5 pushes the ejector pin 3 to slide horizontally through its outer conical surface 5.1; the horizontally sliding ejector pin 3 drives the positioning slider 1 to slide horizontally in the slider support 2.
[0039] To ensure that the ejector pin 3 can always fit tightly against the outer conical surface 5.1 of the core shaft 5, the connecting screw 10 is coaxially mounted with a compression spring 8; the return force of the compression spring 8 is used to ensure that the ejector pin 3 always fits tightly against the outer conical surface 5.1 of the core shaft 5.
[0040] (like Figure 3 As shown, the ejector pin 3, connecting screw 10, compression spring 8, positioning slider 1, and slider support 2 are each provided in three groups. These groups are evenly distributed radially along the centering support 4 at intervals of 120°. Positioning of the workpiece inner hole is achieved by the outer arc positioning surface 1.1 of the positioning slider 1, which is horizontally displaced in the radial direction.
[0041] Among them, the positioning slider 1 is the main positioning component, and the outer arc positioning surfaces 1.1 of the three positioning sliders 1 must be on the same outer circle through process assurance, with an accuracy of up to ±0.03mm.
[0042] In the above embodiment, preferably, the operating portion is a hand wheel 7 or a handle 11 , and rotating the hand wheel 7 or the handle 11 drives the screw rod 12 to rotate.
[0043] In the above embodiment, preferably: (combined with Figure 8 、 Figure 9 As shown) the inner end of the ejector pin 3 is formed with an inclined arc groove 3.1; the inclined arc groove 3.1 is tightly fitted with the outer conical surface 5.1 of the core shaft 5 (as shown Figure 2 The outer conical surface 5.1 of the lifting mandrel 5 drives the ejector pin 3 to achieve horizontal displacement of the ejector pin 3.
[0044] In the above embodiment, preferably: the connecting screw 10 is provided with external threads at both ends and a boss 101 in the middle, and the external threads at both ends of the connecting screw 10 are respectively fixed to the top pin 3 and the internal threaded holes of the positioning slider 1; the threaded connection method facilitates the rapid assembly, disassembly and replacement of the positioning slider 1.
[0045] The middle part of the connecting screw 10 is screwed to fit the adjusting nut 9 ; the compression spring 8 is installed on the outer side of the adjusting nut 9 , and the adjusting nut 9 is used to adjust the resetting elastic force of the compression spring 8 .
[0046] In the above embodiment, as a further improved embodiment of the present invention: (combined with Figure 4 、 Figure 5 As shown, the top of the positioning slider 1 is formed with a linear groove 1.2; a positioning screw 14 is mounted perpendicularly to the slider support 2; the screw head of the positioning screw 14 is a flat head. The positioning screw 14 is inserted into the linear groove 1.2 and moves along the linear groove 1.2. The positioning screw 14 and the linear groove 1.2 provide a linear guide for the linear movement of the positioning slider 1.
[0047] In the above embodiment, preferably: (such as Figure 2(As shown) the installation height of the ejector pin 3 in the centering support 4 is the same as the installation height of the positioning slider 1 in the slider support 2, thereby ensuring that the ejector pin 3 and the positioning slider 1 slide smoothly without jamming.
[0048] In the above embodiment, as a further improvement of the present invention: (as Figure 10 、 Figure 11 As shown) also includes a base 15, and the center of the upper end surface of the base 15 is provided with the inner hole positioning device 16; a plurality of support blocks 17 are radially provided on the periphery of the inner hole positioning device 16; the support blocks 17 are respectively installed with pressure plates 18; the pressure plates 18 are used to press the periphery of the workpiece after the inner hole is positioned, so as to strengthen the fixation.
[0049] In the above embodiment, as a further improvement of the present invention, the base 15 is formed with a keyway and a pressure plate groove 151, and the keyway and the pressure plate groove 151 are used for positioning and pressing the base 15 on the machine tool table.
[0050] As a further improvement to the above embodiment, the present invention further includes an angular positioning device 19, which is positioned adjacent to the inner hole positioning device 16. Angular positioning devices are widely used in fields such as metalworking and mechanical manufacturing, enabling precise positioning of workpieces in a spatial circumferential direction. Processing can be performed at specific angles based on processing requirements. The operating principle of the angular positioning device 19 primarily relies on servo motor drive and sensor detection. When a workpiece is placed on the clamping device, the servo motor begins to operate, driving the clamping device and workpiece to rotate. Simultaneously, the sensor monitors the workpiece's position and angle in real time to ensure that the workpiece accurately reaches the predetermined processing angle. Once the workpiece reaches the predetermined position, the clamping device locks the workpiece to prevent it from shifting or shaking during processing. Therefore, the angular positioning device 19 achieves high-precision angular positioning, ensuring stability and accuracy during the processing. Through servo motor drive and sensor detection, the angular positioning device can be automated, reducing manual intervention and improving production efficiency. The angular positioning device can be applied to workpieces of various shapes and sizes, demonstrating excellent versatility and flexibility. The angular positioning device has a relatively simple structure and is easy to maintain, which can reduce the operating costs of the enterprise.
[0051] The working principle of this utility model is: (as Figure 2 、 Figure 3When clamping and positioning, the handle 11 is manually rotated clockwise, and the handle 11 drives the screw rod 12 to rotate. Since the pressure cover 6 is fixed, the screw rod 12 moves axially downward, and the downward axially displaced screw rod 12 pushes the core shaft 5 to move downward synchronously. In the process of moving downward, the outer conical surface 5.1 of the lower end of the core shaft 5 pushes the three ejector pins 3 in close contact with the outer conical surface 5.1 of the tapered core shaft 5 to move outward in the circumferential direction at the same time. Since the ejector pins 3 are connected to the positioning slider 1 through the connecting screw 10, the outward-displaced ejector pins 3 drive the positioning slider 1 to move outward in the circumferential direction, and finally the purpose of positioning the inner hole of the center of the workpiece is achieved by the outward-displaced positioning slider 1.
[0052] Among them, it should be noted that: it also includes a compression spring 8; the positioning slider 1 is connected to the push pin 3 through a connecting screw 10, and the connecting screw 10 is coaxially mounted with the compression spring 8. The return elastic force of the compression spring 8 makes the push pin 3 always in close and gapless contact with the outer conical surface 5.1 of the core shaft 5, so that the three radially evenly distributed push pins 3 drive the positioning slider 1 to move outward along the radius at the same time in the circumferential direction, and the purpose of quickly clamping and positioning the inner hole of the workpiece is achieved by tightening the inner hole of the workpiece through the three positioning sliders 1 moving outward.
[0053] When the workpiece needs to be disassembled after processing is completed: rotate the handle 11 counterclockwise, the handle 11 drives the screw rod 12 to lift, and the lifted screw rod 12 drives the core shaft 5 to lift. The ejector pin 3, which is always in close contact with the outer conical surface 5.1 of the core shaft 5, is under the action of the restoring elastic force of the compression spring 8, so that the ejector pin 3 drives the positioning slide 1 to retract, thereby canceling the center positioning of the workpiece.
[0054] From the above description, it can be seen that the present invention uses the rotating screw 12 to drive the mandrel 5 up and down. This movement generates radial displacement through the outer conical surface 5.1 at its lower end, thereby pushing the ejector pins 3 and the positioning sliders 1, which are evenly spaced at 120°, to move radially outward simultaneously along the circumference, thereby positioning the workpiece's inner hole. The positioning sliders 1 are the only centering components that contact the workpiece's inner hole. The three outer arc positioning surfaces 1.1 of the three positioning sliders 1 are always distributed on the same circumference during operation and are used to tighten the workpiece's inner hole. The ejector pin 3 is a key component that drives the positioning slider 1 to move. The tail of the ejector pin 3 has an inclined arc groove 3.1 that is highly consistent with the outer conical surface 5.1 of the core shaft 5; the compression spring 8 is used to ensure that the ejector pin 3 always keeps in close contact with the outer conical surface 5.1 of the core shaft 5 when driving the positioning slider 1 to retreat; the ejector pin 3 converts the up and down movement of the core shaft 5 into the linear motion of the positioning slider 1 along the radial direction through the inclined arc groove 3.1 at the tail; and the screw rod 12 converts the rotational motion of the screw rod 12 into the linear lifting motion of the core shaft 5 through the inverted T-shaped groove 5.2 at the head of the core shaft 5.
[0055] To sum up, the utility model has a simple and practical structure, low manufacturing and maintenance costs, easy and quick operation, and can be disassembled and used repeatedly. It can mainly solve the problem of rapid positioning of inner holes with large inner hole sizes (φ300-φ500) and moderate tolerances (±0.1mm); it fills the gap in inner hole positioning processing during small and medium-sized batch processing of shell parts, and at the same time has strong popularization potential.
[0056] The utility model only needs to replace the positioning slide block 1 for workpieces with different hole diameters. The positioning slide block 1 can quickly realize the inner hole positioning and clamping through its process control, and ensure the concentricity to meet the positioning requirements.
[0057] The utility model has a simple structure and is easy to maintain, reduces the processing difficulty from the production perspective, improves the production efficiency, and reduces the product processing cost.
[0058] like Figure 10 、 Figure 11 The figure shows the present invention being applied to the machining of the workpiece shown in FIG1 . The inner hole size of the workpiece to be machined is φ380±0.1mm, and the present invention is used to machine various hole groups on the workpiece. The entire inner hole positioning device 16 is fixed to the base 15, and an angular positioning device 19 is provided on the side of the inner hole positioning device 16. Several support blocks 17 are distributed in an annular manner around the outer periphery of the inner hole positioning device 16, and a pressure plate 18 is located on the support blocks 17. The base 15 is provided with a keyway and a pressure plate groove 151, which are used to position and clamp the base 15 on the machine table. During operation: first place the workpiece on the support block 17, then rotate the handle or handwheel and assist the angular positioning device 19 to quickly and efficiently position and clamp the workpiece for the inner hole. After the inner hole is clamped and positioned, the pressure plate 18 is installed and machining can begin. If the inner hole of the workpiece changes, machining can be carried out by simply replacing the positioning slide 1. This inner hole positioning device 16 is suitable for the clamping and positioning processing of a large class of automotive parts similar to the workpiece in Figure 1 that require rapid inner hole positioning. This structure is also suitable for the clamping and positioning of other types of parts that require inner hole positioning, such as milling, boring, and horizontal processing, and the method of use and the effect are equally obvious. Therefore, the utility model can effectively solve the problem of rapid positioning of inner holes with large inner hole sizes (φ300-φ500) and moderate tolerances (±0.1mm). The special structure changes the direction of force transmission and realizes three-point simultaneous linkage positioning, which has wide applicability; it is also applicable to milling processing, boring machine processing, horizontal processing, etc., and is suitable for promotion.
[0059] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.
[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications and equivalent replacements made within the spirit and principles of the present invention are included in the scope of protection of the present invention.
Claims
1. An inner hole positioning device, characterized in that: The invention has a tooling base (13), wherein the tooling base (13) is fixedly installed with a centering support (4); a pressure cover (6) is installed at the top of the centering support (4); a vertically liftable core shaft (5) is coaxially installed on the inner side of the centering support (4); the top of the core shaft (5) is connected to the bottom end of the screw rod (12); the rod body of the screw rod (12) is screwed to fit the center hole of the pressure cover (6); the top end of the screw rod (12) is fixedly connected to the operating part; the screw rod (12) is rotated to drive the core shaft (5) to rise and fall; the bottom end of the shaft body of the core shaft (5) is formed with an outer conical surface (5.1), and the outer conical surface (5.1) is tightly fitted with one end of a horizontally arranged ejector pin (3); the other end of the ejector pin (3) is connected to the positioning slider (1) through a connecting screw rod (10); the lifting core shaft (5) is moved by its outer conical surface (5.1) ) pushes the ejector pin (3) to slide horizontally; the ejector pin (3) that slides horizontally drives the positioning slider (1) to slide horizontally in the slider support (2); the connecting screw (10) is coaxially mounted with the compression spring (8); the return elastic force of the compression spring (8) is used to make the ejector pin (3) always closely fit the outer conical surface (5.1) of the core shaft (5); the ejector pin (3), the connecting screw (10), the compression spring (8), the positioning slider (1), and the slider support (2) are respectively provided in three groups, and the three groups of ejector pins (3), the connecting screw (10), the compression spring (8), the positioning slider (1), and the slider support (2) are respectively evenly distributed radially along the centering support (4); the inner hole positioning of the workpiece is achieved by the outer arc positioning surface (1.1) of the positioning slider (1) that is horizontally displaced in the radial direction.
2. The inner hole positioning device according to claim 1, characterized in that: The operating part is a hand wheel (7) or a handle (11), and rotating the hand wheel (7) or the handle (11) drives the screw rod (12) to rotate.
3. The inner hole positioning device according to claim 1 or 2, characterized in that: The bottom end of the screw rod (12) is rotatably connected to the inverted T-shaped slot (5.2) formed on the top end of the core shaft (5) through an inverted T-shaped structure, and the core shaft (5) is driven to rise and fall vertically in the centering support (4) by the rotating screw rod (12).
4. The inner hole positioning device according to claim 1, characterized in that: The inner end of the ejector pin (3) is formed with an inclined circular arc groove (3.1); the inclined circular arc groove (3.1) is tightly fitted with the outer conical surface (5.1) of the core shaft (5); the outer conical surface (5.1) of the ascending and descending core shaft (5) drives the ejector pin (3) to achieve horizontal displacement of the ejector pin (3).
5. The inner hole positioning device according to claim 1, characterized in that: The connecting screw rod (10) is provided with external threads at both ends and a boss (101) in the middle. The external threads at both ends of the connecting screw rod (10) are respectively fixed to the top pin (3) and the internal threaded hole of the positioning slide block (1); the middle part of the connecting screw rod (10) is screwed to fit and install the adjusting nut (9); the compression spring (8) is installed on the outside of the adjusting nut (9).
6. The inner hole positioning device according to claim 1, characterized in that: A linear slide groove (1.2) is formed at the top of the positioning slider (1); a positioning screw (14) is vertically installed on the slider support (2); the positioning screw (14) is inserted into the linear slide groove (1.2) and moves along the linear slide groove (1.2); the positioning screw (14) and the linear slide groove (1.2) provide a linear guide for the linear displacement of the positioning slider (1).
7. The inner hole positioning device according to claim 1, characterized in that: The installation height of the ejector pin (3) in the centering support (4) is the same as the installation height of the positioning slider (1) in the slider support (2).
8. The inner hole positioning device according to claim 1, characterized in that: The invention also includes a base (15), wherein the center of the upper end surface of the base (15) is provided with the inner hole positioning device (16); a plurality of support blocks (17) are radially provided on the periphery of the inner hole positioning device (16); the support blocks (17) are respectively installed with pressure plates (18); the pressure plates (18) are used to press the periphery of the workpiece after the inner hole is positioned.
9. The inner hole positioning device according to claim 8, characterized in that: The base (15) is provided with a keyway and a pressure plate groove (151), and the keyway and the pressure plate groove (151) are used for positioning and pressing the base (15) on the machine tool table.
10. The inner hole positioning device according to claim 1, characterized in that: It also includes an angular positioning device (19); the angular positioning device (19) is arranged beside the inner hole positioning device (16).