Positioning clamp for eccentric crankshaft

Abstract

The utility model relates to a positioning fixture for an eccentric crankshaft, which comprises a base, and a first positioning column, a second positioning column and a third positioning column are arranged on the base. The positioning block and the first positioning column are detachably arranged on the base in a matched mode. The positioning block is provided with a first hole in the first direction, the first hole penetrates through the positioning block in the first direction, and the second positioning column is arranged on the base with the central axis of the first hole as the center. The axes of the two ends of the eccentric crankshaft are controlled on the same plane perpendicular to the base through the positioning block and the second positioning column to be machined, and the machining precision and the product quality are improved.

Description

Technical Field

[0001] The utility model relates to the field of part positioning tooling, in particular to a positioning fixture for an eccentric crankshaft. Background Art

[0002] As one of the key parts of the engine, the crankshaft has a complex structure, large production batches, frequent product changes, and high precision requirements. This requires the crankshaft to have sufficient strength and rigidity, and the journal surface must be wear-resistant, work evenly, and have good balance. In the process of producing crankshafts, it is often necessary to mill the crankshafts, but because the crankshaft is eccentric, the position of the groove directly processed by the traditional method cannot meet the process requirements, and it is easy to have position processing errors and low precision problems. Therefore, it is necessary to design a fixture that can quickly find the center of the crankshaft and can be fixed to achieve high-precision processing and production of the crankshaft. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present utility model is to provide a positioning fixture for an eccentric crankshaft to solve one or more problems in the prior art.

[0004] To achieve the above purpose, the technical solution of the utility model is as follows:

[0005] A positioning fixture for an eccentric crankshaft comprises a base, on which a first positioning column, a second positioning column and a third positioning column are respectively arranged; a positioning block is detachably arranged on the base in cooperation with the first positioning column; the positioning block is provided with a first hole along a first direction, the first hole passes through the positioning block along the first direction, and adjacent second positioning columns are arranged on both sides of the base with the central axis of the first hole as the center.

[0006] Furthermore, the positioning fixture for the eccentric crankshaft also includes a sleeve, and the sleeve is clearance-matched with the first hole.

[0007] Furthermore, the positioning block is provided with a second hole in a second direction away from the base and perpendicular to the first direction, the second hole is communicated with the first hole, and a screw is connected in the second hole.

[0008] Furthermore, an inner thread is provided on the inner surface of the second hole, and the screw is threadedly matched with the second hole.

[0009] Furthermore, the sleeve includes a third hole and a fourth hole, the third hole passes through the sleeve, and the fourth hole is opened along the axial direction of the sleeve.

[0010] Furthermore, the screw introduction portion is connected to a sheath, and the inner side of the sheath is gap-matched with the screw.

[0011] Furthermore, the outer side of the sheath is gap-matched with the fourth hole.

[0012] Furthermore, the base is provided with a positioning hole.

[0013] Compared with the prior art, the beneficial technical effects of the utility model are as follows:

[0014] (i) The crankshaft is fixed by setting a second positioning column and a positioning block on the base, setting one end of the crankshaft in the second positioning column, and setting the other end in the positioning block. While ensuring that the crankshaft is fixed, the axis centers of both ends of the crankshaft are always kept on the plane vertical to the bottom surface, which makes it convenient for operators to find the center of the crankshaft, and then quickly set the reference to facilitate further processing in the machining center, effectively improving the machining efficiency.

[0015] (ii) By adding a sleeve to the screw guide portion, the friction with the crankshaft contact surface is reduced when the screw is used to tighten the crankshaft to be processed, thereby protecting the outer side of the crankshaft product from wear, ensuring the yield rate of the crankshaft product, and improving the processing quality of the crankshaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A structural schematic diagram of a positioning fixture for an eccentric crankshaft according to an embodiment of the utility model is shown.

[0017] Figure 2 A schematic structural diagram of a positioning block of a positioning fixture for an eccentric crankshaft according to an embodiment of the utility model is shown.

[0018] Figure 3 A schematic diagram of the sleeve structure of a positioning fixture for an eccentric crankshaft according to an embodiment of the utility model is shown.

[0019] Figure 4 A schematic diagram of the screw and sleeve structure of a positioning fixture for an eccentric crankshaft according to an embodiment of the utility model is shown.

[0020] Figure 5 A schematic diagram showing the eccentric placement of both ends of a crankshaft of a positioning fixture for an eccentric crankshaft according to an embodiment of the utility model is shown.

[0021] Figure 6 A schematic diagram showing the concentric placement of the two ends of a crankshaft of a positioning fixture for an eccentric crankshaft according to an embodiment of the utility model is shown.

[0022] Markings in the accompanying drawings: 1. base; 101. first positioning column; 102. second positioning column; 103. third positioning column; 104. positioning hole; 2. positioning block; 201. first hole; 202. second hole; 2021. internal thread; 3. sleeve; 301. third hole; 302. fourth hole; 4. screw; 5. sheath. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the utility model clearer, the following is a further detailed description of a positioning fixture for an eccentric crankshaft proposed by the utility model in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the utility model will be clearer. It should be noted that the accompanying drawings adopt a very simplified form and all use non-precise proportions. The orientation or position relationship indicated by the terms "center", "lateral", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "side" and the like is based on the orientation or position relationship shown in the accompanying drawings, rather than indicating or implying that the positioning fixture or element for an eccentric crankshaft referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model, but is only used to conveniently and clearly assist in explaining the purpose of the implementation method of the utility model. In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, please refer to the accompanying drawings.

[0024] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions for the implementation of the utility model, so they have no substantive technical significance. Any modification of the structure, change in the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the utility model without affecting the effects and purposes that can be achieved by the utility model.

[0025] The specific structure of a positioning fixture for an eccentric crankshaft is described below:

[0026] See also Figure 1 The positioning fixture for the eccentric crankshaft of this embodiment includes a base 1, on which a first positioning column 101, a second positioning column 102 and a third positioning column 103 are arranged. Preferably, two first positioning columns 101, four second positioning columns 102 and two third positioning columns 103 are arranged in this embodiment. The positioning block 2 cooperates with the first positioning column 101, and the positioning block 2 is detachably arranged on the base 1. The first positioning column 101 limits the displacement of the positioning block 2 in the front-back direction, and the third positioning column 103 limits the displacement of the positioning block 2 in the left direction so that the positioning block 2 can be adjusted in one direction. The base 1 is also provided with a positioning hole 104. Preferably, two positioning holes 104 are arranged in this embodiment. The positioning holes 104 cooperate with the processing machine to limit the displacement of the fixture for accurate processing and ensure the processing quality.

[0027] Please continue reading Figures 1 to 3The positioning block 2 is provided with a first hole 201 along a first direction, the first direction being the left-right direction of the fixture, the first hole 201 passing through the positioning block 2 along the first direction, and the second positioning column 102 is symmetrically arranged on the base 1 with the central axis of the first hole 201 as the center. The first hole 201 is provided with a sleeve 3, and the sleeve 3 is clearance-matched with the first hole 201. One end of the crankshaft is arranged in the sleeve 3, and the other end is arranged between the two second positioning columns 102. The position of the crankshaft is adjusted by rotation so that the centers of the two ends of the crankshaft are always kept on a plane perpendicular to the bottom surface through the second positioning columns 102 and the sleeve 3. The sleeve 3 includes a third hole 301 and a fourth hole 302. The third hole 301 is arranged along the first direction and passes through the sleeve 3. Preferably, the aperture size of the third hole 301 is adjustable and is arranged according to the shaft diameter of the crankshaft. The fourth hole 302 is arranged along the second direction and is formed into a hole surface of the third hole 301, and the second direction is a direction perpendicular to the base 1.

[0028] Please continue reading Figures 1 to 4 The positioning block 2 is also provided with a second hole 202 on its upper surface along the second direction. The second hole 202 is formed along the second direction toward the direction close to the base 1 to the hole surface of the first hole 201. The second hole 202 is connected with a screw 4. The inner surface of the second hole 202 is provided with an internal thread 2021. The screw 4 is threadedly matched with the second hole 202. The introduction portion of the screw 4 is connected with a sleeve 5. The sleeve 5 is clearance-matched with the screw 4. The sleeve 5 is clearance-matched with the fourth hole 302. Preferably, in this embodiment, the inner diameter of the sleeve 5 is slightly larger than the outer diameter of the introduction portion of the screw 4, and the outer diameter of the sleeve 5 is slightly smaller than the inner diameter of the fourth hole 302 to facilitate fixing one end of the crankshaft in the sleeve 3 by tightening the screw 4.

[0029] The specific working process of the positioning fixture for an eccentric crankshaft described in the embodiment of the utility model is described as follows:

[0030] Place the positioning block 2 between the front and rear first positioning columns 101, compare and select the inner diameter of the sleeve 3 with the end of the crankshaft to be processed, and select a suitable sleeve 3. Place the sleeve 3 in the first hole 201, and screw the screw 4 into the second hole 202 and calibrate it into the fourth hole 302 by adjusting the position of the positioning block 2 and the sleeve 3. Figure 5 and Figure 6 , place one end of the crankshaft to be processed into the third hole 301, and insert the other end between the two second positioning columns 102 by rotating and adjusting the crankshaft until the centers of both ends of the shaft remain on a plane perpendicular to the bottom surface. Tighten the screw 4 to fix one end of the crankshaft in the sleeve 3. Take the fixture to the processing machine, and position and fix the positioning hole 104 to the processing machine for processing.

[0031] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0032] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A positioning fixture for an eccentric crankshaft, comprising a base, characterized in that: The base is respectively provided with a first positioning column, a second positioning column and a third positioning column; the positioning block is detachably arranged on the base in cooperation with the first positioning column; the positioning block is provided with a first hole along a first direction, the first hole penetrates the positioning block along the first direction, and the adjacent second positioning columns are arranged on both sides of the base with the central axis of the first hole as the center.

2. A positioning fixture for an eccentric crankshaft as claimed in claim 1, characterized in that: The positioning fixture for the eccentric crankshaft also includes a sleeve, and the sleeve is clearance-matched with the first hole.

3. A positioning fixture for an eccentric crankshaft as claimed in claim 2, characterized in that: The positioning block is further provided with a second hole in a second direction away from the base and perpendicular to the first direction, the second hole is communicated with the first hole, and a screw is connected in the second hole.

4. A positioning fixture for an eccentric crankshaft as claimed in claim 3, characterized in that: An inner surface of the second hole is provided with an internal thread, and the screw is threadedly matched with the second hole.

5. A positioning fixture for an eccentric crankshaft as claimed in claim 4, characterized in that: The sleeve includes a third hole and a fourth hole, the third hole passes through the sleeve, and the fourth hole is opened along the axial direction of the sleeve.

6. A positioning fixture for an eccentric crankshaft as claimed in claim 5, characterized in that: The screw introduction portion is connected with a sheath, and the inner side of the sheath is gap-matched with the screw.

7. A positioning fixture for an eccentric crankshaft as claimed in claim 6, characterized in that: The outer side of the sheath is loosely matched with the fourth hole.

8. The positioning fixture for an eccentric crankshaft according to claim 1, characterized in that: The base is also provided with a positioning hole.

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