Rapid self-centering clamp for rough machining of double-hole casting blank

Abstract

The rapid self-centering clamp for rough machining of the double-hole casting blank comprises a bottom plate, a fixed side centering unit, a movable side centering unit and a plurality of side top units, the fixed side centering unit and the movable side centering unit are installed on the bottom plate in a front-and-back mode, and the side top units are installed on the bottom plate in a left-and-right mode. The fixed side centering unit comprises a first tip, a first tip seat and a first screw rod, the first screw rod transversely penetrates through the first tip seat and is in threaded connection with the first tip seat, the first tip is fixed to the front end of the first screw rod, the first tip seat is fixed to the bottom plate, and the movable side centering unit comprises a second tip, a second tip seat and a second screw rod; the second screw transversely penetrates through the second center seat and is in threaded connection with the second center seat, the second center is fixed to the front end of the second screw, and the second center seat is installed on the bottom plate in a front-back sliding mode. The clamp is low in machining cost and convenient and flexible to use, rapid clamping and rapid self-centering of rough machining of the double-hole casting blank can be achieved, the clamping alignment time is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to a fixture, specifically a quick self-centering fixture for rough machining of double-hole casting blanks. Background Technology

[0002] Rough machining of perforated castings is the first step in their machining process. Typically, simple tools commonly found in the workshop are used for clamping, depending on the size of the casting blank. Specialized rough machining fixtures are rare. Before machining, allowances are usually allocated according to the holes, and alignment is performed. Due to the poor surface finish of the casting blank and the difficulty in controlling the allowance, clamping and calculating the allocated allowances during rough machining usually takes a considerable amount of time, or allowances are pre-allocated by scribing, resulting in lengthy alignment times. If the casting blank has a double-hole structure, even more time is required for alignment, leading to low clamping efficiency and significantly impacting production efficiency, especially for parts produced in large batches with high machining volumes.

[0003] CN222471636U discloses a hydraulic clamping fixture for rough machining of a left steering knuckle, including a clamping body. The clamping body has a first-end locating pin, a second-end locating pin, and a third-end locating pin arranged in a triangle. A vertically moving chamfering locating pin is arranged on the line connecting the first and third-end locating pins. The clamping body has a side locating seat with a horizontally arranged locating screw. A pressure plate is correspondingly arranged above each of the first, second, and third-end locating pins. A horizontally moving side pressure head is arranged directly opposite the locating screws. This clamping fixture uses hydraulic cylinders to drive key structures such as the side pressure head, locking mechanism, and chamfering locating pin, resulting in high cost. The fixture structure is complex and expensive to manufacture, and it can only be used for rough machining clamping of left steering knuckles, exhibiting poor versatility. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a quick self-centering fixture for rough machining of double-hole casting blanks, which is low in processing cost, convenient and flexible to use, and can realize quick clamping and quick self-centering of double-hole casting blanks for rough machining, shorten the clamping and alignment time of double-hole casting blanks, and improve the production efficiency of double-hole casting blanks.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a quick self-centering fixture for rough machining of double-hole casting blanks, including a base plate, a fixed-side centering unit, a movable-side centering unit, and multiple side-top units. The fixed-side centering unit and the movable-side centering unit are installed on the base plate with a front-to-back gap. The multiple side-top units are installed on the base plate with a left-to-right gap. The fixed-side centering unit includes a first center, a first center seat, and a first screw. The first screw passes through the first center seat and is threadedly connected to the first center seat. The first center is coaxially fixed to the front end of the first screw. The first center seat is fixed to the base plate. The movable-side centering unit includes a second center, a second center seat, and a second screw. The second screw passes through the second center seat and is threadedly connected to the second center seat. The second center is coaxially fixed to the front end of the second screw. The second center seat is slidably installed on the base plate. The first center and the second center are used for front-to-back centering and clamping the front and rear aligned holes of the double-hole casting blank to be clamped. The multiple side-top units are used for left-to-right clamping of the double-hole casting blank.

[0006] This utility model fixture uses the front and rear aligned holes of a double-hole casting blank as a reference. The first and second centers center and clamp the aligned holes of the double-hole casting blank from the front and rear, while multiple side-mounted units clamp the double-hole casting blank from the left and right. This achieves rapid clamping and self-centering of the double-hole casting blank during rough machining, shortening the clamping and alignment time and improving the production efficiency of double-hole casting blanks. The distance between the first and second centers can be easily adjusted by rotating the first and second screws, making operation convenient and meeting the clamping needs of double-hole casting blanks of different lengths.

[0007] The components of this utility model fixture do not have high precision requirements, have low processing costs, are convenient and flexible to use, and meet the clamping needs for rough machining of double-hole casting blanks of different specifications within a certain size range.

[0008] Preferably, the first center seat is trapezoidal, wider at the bottom than the top. The first center seat has a front-to-back threaded hole, two vertically connected countersunk holes, and two locating pin holes. The threaded hole is used to install the first screw, and the two countersunk holes are used to install two first screws, which are threadedly connected to the base plate. The two locating pin holes are located at the bottom of the first center seat and are used to install two locating pins, which are then locatingly connected to the base plate. The first center seat is installed on the base plate using two first screws and two locating pins, making operation convenient and installation reliable. The countersunk hole design facilitates the installation of the first screws.

[0009] Preferably, the upper part of the base plate has two T-slots arranged parallel to each other. Two T-blocks are fixed to the bottom of the second center seat, each T-block being slidably connected to one of the T-slots. The T-blocks, in conjunction with the T-slots, enable the second center seat to be mounted on the base plate. This guides the forward and backward sliding of the second center seat while restricting its lateral freedom. The structure is simple and reliable.

[0010] Furthermore, the second center seat is trapezoidal, wider at the bottom than the top. The second center seat has a second threaded hole that extends from front to back and two second countersunk holes that extend vertically. The second threaded hole is used to install the second screw, and the two second countersunk holes are used to install two second screws. Each second screw is threadedly connected to one of the T-blocks. The design of the second countersunk holes facilitates the installation of the second screws.

[0011] Preferably, the first screw and the second screw have the same structure, each including a first external threaded section, a second external threaded section, and an external hexagonal section integrally formed at both ends. The first center and the second center are respectively threadedly connected to a section of the first external threaded section, and the first center seat and the second center seat are respectively threadedly connected to a section of the second external threaded section. The diameter of the second external threaded section is larger than the diameter of the first external threaded section. The first external threaded section is used to lock the first center or the second center, the second external threaded section is used to adjust the relative position of the first center and the second center, and the external hexagonal section is used to facilitate rotational adjustment of the first screw or the second screw.

[0012] Preferably, each side-top unit includes a support base, a support pin, and a side-top mechanism. The support base is fixed to the base plate, the support pin is vertically mounted on the support base, and the side-top mechanism is mounted on the top of the support base. The support pin supports the bottom of the double-hole casting blank, and the side-top mechanism abuts against the side of the double-hole casting blank. The support base and side-top mechanism enable positioning of the double-hole casting blank in different directions, ensuring the reliability of the double-hole casting blank clamping.

[0013] Preferably, the side-top mechanism includes a side-top block, a positioning block, and a side-top screw. The positioning block is fixed to the top of the support base. The end face of the positioning block facing the double-hole casting blank is a first inclined surface sloping downwards towards the middle of the base plate. A half-threaded hole is provided on the first inclined surface. A second inclined surface is provided on the back of the side-top block, which is parallel to the first inclined surface. A half-open hole and a groove are provided on the second inclined surface. The half-open hole is located on the upper part of the second inclined surface. The half-threaded hole and the half-open hole together form a groove. The device comprises an operating hole and a groove located below the half of the open hole. The radius of the operating hole is smaller than the depth of the groove. The side-mounted screw is an internal hexagon screw, with its radial rear half threadedly connected to the half of the threaded hole. The radial front half of the side-mounted screw is confined within the groove. The two axial end faces of the side-mounted screw face the top and bottom surfaces of the groove, respectively. The front of the side-mounted block serves as a top surface for clamping the side of the double-hole casting blank. Multiple parallel elongated grooves are provided on the top surface. The aforementioned side-mounted mechanism has a simple structure, facilitating the adjustment of the side-mounted block's left and right position, thereby quickly achieving the clamping operation on the side of the double-hole casting blank. During adjustment, simply insert a wrench into the operating hole, rotate the side top screw, and while the side top screw moves obliquely along half of the threaded hole, apply an oblique pushing or pulling force to the side top block, thereby realizing the left and right translation of the side top block and achieving the purpose of adjusting the left and right position of the side top block, so as to better match the width dimension of the double-hole casting blank and improve the clamping accuracy and clamping reliability.

[0014] Preferably, the positioning block is pressed and fixed to the top of the support base by positioning screws. The positioning block has an oblong hole with its major axis running left-right, and the positioning screw is disposed in the oblong hole. The oblong hole design facilitates the left-right adjustment of the positioning block's installation position on the support base, thereby adjusting the distance between the side top mechanisms on the left and right sides of the base plate to meet the clamping requirements of double-hole casting blanks of different widths.

[0015] Furthermore, the support pin includes a square segment and a threaded segment integrally formed on both sides. The threaded segment is threadedly connected to the support base. The square segment has multiple through holes for tightening the support pin with an Allen wrench. The top surface of the square segment serves as a support surface for supporting the bottom of the double-hole casting blank. The height of the support pin is easily adjustable, which helps to further improve the clamping accuracy of the double-hole casting blank.

[0016] Preferably, the support surface is a toothed surface with multiple positioning teeth to ensure that the support surface is in full contact with the double-hole casting blank and to achieve reliable support for the double-hole casting blank.

[0017] Compared with existing technologies, this utility model has the following advantages: The rapid self-centering fixture for rough machining of double-hole casting blanks uses the front and rear aligned holes of the double-hole casting blank as a reference. It uses a first and second center to center and clamp the front and rear aligned holes of the double-hole casting blank, and multiple side-clamping units to clamp the double-hole casting blank from left and right. This achieves rapid clamping and rapid self-centering for rough machining of double-hole casting blanks, shortening the clamping and alignment time and improving the production efficiency of double-hole casting blanks. The fixture's components do not require high precision, have low processing costs, are convenient and flexible to use, and meet the clamping needs for rough machining of double-hole casting blanks of different specifications within a certain size range. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the appearance of the rapid self-centering fixture in the embodiment;

[0019] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0020] Figure 3 This is a schematic longitudinal section of a single side-top unit in the embodiment;

[0021] Figure 4 for Figure 3 Enlarged view at point B in the middle;

[0022] Figure 5 This is a schematic diagram of the appearance of the base plate in the embodiment;

[0023] Figure 6 This is a partial sectional front view of the first center seat in the embodiment;

[0024] Figure 7 This is a partial sectional front view of the first screw or the second screw in the embodiment;

[0025] Figure 8 This is a schematic diagram of the appearance of a single support nail in the embodiment;

[0026] Figure 9 This is a schematic diagram showing the clamping state of the bearing housing blank in the embodiment;

[0027] The specific reference numerals in the figure are as follows:

[0028] 1-Base plate, 11-T-slot, 2-Fixed side centering unit, 21-First center, 22-First center seat, 23-First screw, 24-First threaded hole, 25-First countersunk hole, 26-Locating pin hole, 3-Moving side centering unit, 31-Second center, 32-Second center seat, 33-Second screw, 4-Side top unit, 41-Support seat, 42-Support pin, 43-Square segment, 44-Threaded segment, 45-Through hole, 46-Support surface, 47-Positioning tooth, 51-First external thread section, 52-Second external thread section, 53-External hexagonal section, 61-Side top block, 611-Side top surface, 612-Long groove, 62-Positioning block, 63-Side top screw, 64-Positioning screw, 65-Oval hole, 66-First inclined surface, 67-Half threaded hole, 68-Second inclined surface, 69-Half smooth hole, 60-Groove, 601-Top surface, 602-Bottom surface, 7-Operating hole, 8-Bearing seat blank. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Components or structures not limited in this invention employ conventional techniques in the art.

[0030] The embodiment of the quick self-centering fixture for rough machining of double-hole casting blanks, such as Figure 1 As shown, the system includes a base plate 1, a fixed-side centering unit 2, a movable-side centering unit 3, and six side-top units 4. The fixed-side centering unit 2 and the movable-side centering unit 3 are installed on the base plate 1 at intervals, while the six side-top units 4 are installed on the base plate 1 at intervals. The fixed-side centering unit 2 includes a first center 21, a first center seat 22, and a first screw 23. The first screw 23 passes through the first center seat 22 and is threadedly connected to it. The first center 21 is coaxially fixed to the front end of the first screw 23. The first center seat... 22 is fixed on the base plate 1. The movable side centering unit 3 includes a second center 31, a second center seat 32, and a second screw 33. The second screw 33 passes through the second center seat 32 and is threadedly connected to the second center seat 32. The second center 31 is coaxially fixed to the front end of the second screw 33. The second center seat 32 can be slidably mounted on the base plate 1. The first center 21 and the second center 31 are used for front and rear centering and pressing the front and rear aligned holes of the double-hole casting blank to be clamped. The six side top units 4 are used for left and right clamping of the double-hole casting blank.

[0031] In this embodiment, the first top seat 22 is a trapezoid with a smaller top and a larger bottom to ensure stability; for example... Figure 6As shown, the first center seat 22 has a first threaded hole 24 that is open from front to back, two first countersunk holes 25 that are open from top to bottom, and two locating pin holes 26. The first threaded hole 24 is used to install the first screw 23, and the two first countersunk holes 25 are used to install two first screws (not shown in the figure). The two first screws are threadedly connected to the base plate 1. The two locating pin holes 26 are located at the bottom of the first center seat 22. The two locating pin holes 26 are used to install two locating pins (not shown in the figure). The two locating pins are locatingly connected to the base plate 1.

[0032] In this embodiment, as Figure 5 As shown, the upper part of the base plate 1 has two T-slots 11, which are arranged parallel to each other. Two T-blocks (not shown in the figure) are fixed to the bottom of the second center seat 32, each T-block being slidably connected to one of the T-slots 11. The second center seat 32 is a trapezoid with a smaller top and a larger bottom to ensure stability. (See also...) Figure 6 The second center seat 32 has a second threaded hole that is open from front to back and two second countersunk holes that are open from top to bottom. The second threaded hole is used to install the second screw 33, and the two second countersunk holes are used to install two second screws (not shown in the figure). Each second screw is threadedly connected to a T-block.

[0033] In this embodiment, as Figure 7 As shown, the first screw 23 and the second screw 33 have the same structure, both including a first external thread section 51, a second external thread section 52 and an external hexagonal section 53 integrally formed at the front and rear. The first center 21 and the second center 31 are respectively threaded to a section of the first external thread section 51, and the first center seat 22 and the second center seat 32 are respectively threaded to a section of the second external thread section 52. The diameter of the second external thread section 52 is larger than the diameter of the first external thread section 51.

[0034] In this embodiment, the first center 21, the second center 31, the first screw 23, and the second screw 33 are all integrally quenched to ensure hardness. The first center 21 and the second center 31 are both solid centers, and the only requirement is to ensure the surface finish of the conical surface.

[0035] In this embodiment, as Figures 2-4 As shown, each side-top unit 4 includes a support base 41, a support pin 42, and a side-top mechanism. The support base 41 is fixed to the base plate 1, the support pin 42 is vertically mounted on the support base 41, and the side-top mechanism is mounted on the top of the support base 41. The support pin 42 is used to support the bottom of the double-hole casting blank, such as... Figure 8As shown, the support pin 42 includes a square segment 43 and a threaded segment 44 integrally formed. The threaded segment 44 is threadedly connected to the support base 41. The square segment 43 has four through holes 45 at 45° intervals for turning the support pin 42 with an Allen wrench. The top surface of the square segment 43 is a support surface 46 for supporting the bottom of the double-hole casting blank. The support surface 46 is a toothed surface with multiple positioning teeth 47. The side-top mechanism is used to press the side of the double-hole casting blank. Specifically, the side-top mechanism includes a side-top block 61, a positioning block 62, and a side-top screw 63. The positioning block 62 is pressed and fixed to the top of the support base 41 by the positioning screw 64. The positioning block 62 has a waist-shaped hole 65 with its long axis along the left-right direction. The positioning screw 64 is located in the waist-shaped hole 65. The end face of the positioning block 62 facing the double-hole casting blank is a first inclined surface 66 that slopes downwards towards the middle of the bottom plate 1. The top of the side top block 61 has a half threaded hole 67. The back of the side top block 61 has a second inclined surface 68, which is parallel to the first inclined surface 66. The second inclined surface 68 has a half smooth hole 69 and a groove 60. The half smooth hole 69 is located on the upper part of the second inclined surface 68. The half threaded hole 67 and the half smooth hole 69 are combined into an operating hole 7. The groove 60 is located on the lower side of the half smooth hole 69. The radius of the operating hole 7 is smaller than the groove depth of the groove 60. The side top screw 63 is an internal hexagon screw. The radial rear half of the side top screw 63 is threaded to the half threaded hole 67. The radial front half of the side top screw 63 is limited to the groove 60. The two axial end faces of the side top screw 63 are respectively facing the top surface 601 and the bottom surface 602 of the groove 60. The front of the side top block 61 is a side top surface 611 for pressing the side of the double-hole casting blank. The side top surface 611 has multiple parallel long grooves 612.

[0036] Using a bearing housing blank 8 as the clamping object, the above-mentioned quick self-centering fixture is used for rough machining. The effect of clamping the bearing housing blank 8 is shown in the figure. Figure 9 .like Figure 9 As shown, the first center 21 and the second center 31 center and clamp the bearing housing blank 8 at the front and rear, respectively, while the six side-mounting units 4 clamp the bearing housing blank 8 from the left and right. Rotating each support pin 42 adjusts the height of each support pin 42, ensuring that the support surface 46 at the top of each support pin 42 is in full contact with the bottom of the bearing housing blank 8. Loosening the positioning screw 64 allows for overall adjustment of the left and right position of the side-mounting mechanism to meet the clamping needs of bearing housing blanks 8 with different widths. Rotating the side-mounting screw 63 allows the side-mounting screw 63 to move obliquely along half of the threaded hole 67 and apply an oblique pushing or pulling force to the side-mounting block 61, thereby achieving the left and right translation of the side-mounting block 61 and adjusting its left and right position to better match the width of the bearing housing blank 8, improving clamping accuracy and reliability.

[0037] For a single bearing housing blank 8, under the conventional clamping method in the workshop, the alignment process alone takes 10 to 20 minutes during a single clamping operation, resulting in low clamping efficiency. After using the quick self-centering fixture of this utility model, the clamping time for the bearing housing blank 8 is reduced to 2 to 5 minutes, which greatly improves clamping efficiency, accuracy, and reliability, and is conducive to improving production efficiency.

Claims

1. A quick self-centering fixture for rough machining of double-hole casting blanks, characterized in that, The system includes a base plate, a fixed-side centering unit, a movable-side centering unit, and multiple side-top units. The fixed-side centering unit and the movable-side centering unit are installed on the base plate with a front-to-back gap. The multiple side-top units are installed on the base plate with a left-to-right gap. The fixed-side centering unit includes a first center, a first center seat, and a first screw. The first screw passes through the first center seat and is threaded to the first center seat. The first center is coaxially fixed to the front end of the first screw. The first center seat is fixed to the base plate. The movable-side centering unit includes a second center, a second center seat, and a second screw. The second screw passes through the second center seat and is threaded to the second center seat. The second center is coaxially fixed to the front end of the second screw. The second center seat is slidably installed on the base plate. The first center and the second center are used for front-to-back centering and clamping the front and rear aligned holes of the double-hole casting blank to be clamped. The multiple side-top units are used for left-to-right clamping of the double-hole casting blank.

2. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 1, characterized in that, The first center seat is a trapezoid with a smaller top and a larger bottom. The first center seat has a first threaded hole that is open from front to back, two first countersunk holes that are open from top to bottom, and two locating pin holes. The first threaded hole is used to install the first screw, and the two first countersunk holes are used to install two first screws. The two first screws are threadedly connected to the base plate. The two locating pin holes are located at the bottom of the first center seat and are used to install two locating pins. The two locating pins are locatingly connected to the base plate.

3. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 1, characterized in that, The upper part of the base plate has two T-shaped grooves, which are arranged in parallel left and right. The bottom of the second center seat has two T-shaped blocks, and each T-shaped block is slidably connected to one of the T-shaped grooves.

4. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 3, characterized in that, The second center seat is a trapezoid with a smaller top and a larger bottom. The second center seat has a second threaded hole that is open from front to back and two second countersunk holes that are open from top to bottom. The second threaded hole is used to install the second screw, and the two second countersunk holes are used to install two second screws. Each second screw is threadedly connected to a T-block.

5. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 1, characterized in that, The first screw and the second screw have the same structure, both including a first external thread section, a second external thread section and an external hexagonal section integrally formed at the front and rear. The first center and the second center are respectively threaded to a section of the first external thread section, and the first center seat and the second center seat are respectively threaded to a section of the second external thread section. The diameter of the second external thread section is larger than the diameter of the first external thread section.

6. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 1, characterized in that, Each of the side-top units includes a support base, a support pin, and a side-top mechanism. The support base is fixed to the base plate, the support pin is vertically mounted on the support base, and the side-top mechanism is mounted on the top of the support base. The support pin is used to support the bottom of the double-hole casting blank, and the side-top mechanism is used to press against the side of the double-hole casting blank.

7. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 6, characterized in that, The side-top mechanism includes a side-top block, a positioning block, and a side-top screw. The positioning block is fixed to the top of the support base. The end face of the positioning block facing the double-hole casting blank is a first inclined surface sloping downwards towards the middle of the base plate. A half-threaded hole is provided on the first inclined surface. A second inclined surface is provided on the back of the side-top block, which is parallel to the first inclined surface. A half-open hole and a groove are provided on the second inclined surface. The half-open hole is located at the upper part of the second inclined surface, and the half-threaded hole and the half-open hole are combined into one. An operating hole is provided, and the groove is located on the lower side of the half-hole. The radius of the operating hole is smaller than the groove depth. The side-top screw is an internal hexagon screw. The radial rear half of the side-top screw is threadedly connected to the half-threaded hole. The radial front half of the side-top screw is confined within the groove. The two axial end faces of the side-top screw are respectively facing the top and bottom surfaces of the groove. The front of the side-top block is a side-top surface used to press against the side of the double-hole casting blank. Multiple parallel long grooves are provided on the side-top surface.

8. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 7, characterized in that, The positioning block is pressed and fixed to the top of the support base by positioning screws. The positioning block has an oblong hole with the long axis of the oblong hole running in the left-right direction. The positioning screw is set in the oblong hole.

9. A quick self-centering fixture for rough machining of double-hole casting blanks according to claim 6, characterized in that, The support pin includes a square segment and a threaded segment integrally formed on the upper and lower parts. The threaded segment is threadedly connected to the support base. The square segment has multiple through holes for an Allen wrench to turn the support pin. The top surface of the square segment is a support surface for supporting the bottom of the double-hole casting blank.

10. The quick self-centering fixture for rough machining of double-hole casting blanks according to claim 9, characterized in that, The support surface is a toothed surface with multiple positioning teeth.

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