A fixture for a machine tool used in hardware processing

Abstract

The present invention relates to the field of machine tool fixtures, in particular to a fixture for a machine tool used in hardware processing, including an assembly table. Press plates for pressing and fixing workpieces are provided at the four corners of the assembly table, and a support assembly is fixedly inserted into the tabletop of the assembly table. The top end of the support assembly abuts against the bottom surface of the workpiece. The support assembly includes an outer cylinder with an opening facing downward. A slideway is provided on the inner wall of the outer cylinder. The trend of the slideway at the top of the outer cylinder is an arc path, and the slideway smoothly transitions from one end of the arc path to a spiral path downward. The present invention is improved on the basis of the existing press plate type fixture. By improving the traditional fixed-height shim block into a support assembly, it can not only provide a reliable support effect with high rigidity for workpiece processing, but also the support assembly corresponding to the processing position can flexibly and actively expand and contract, providing a flexible and safe working space for the tool, greatly improving the operation convenience and flexibility of the traditional press plate type fixture.

Description

Technical Field

[0001] The present invention relates to the field of machine tool fixtures, and particularly to a machine tool fixture for hardware processing. Background Art

[0002] In hardware processing, when drilling and tapping flat workpieces, the cutting tool often needs to penetrate the workpiece. Due to the shape characteristics of flat workpieces, it is generally not suitable to directly clamp the workpiece from both sides to the middle (the middle part of the workpiece is thin and prone to bulge). The common fixing method is to set equal-height pads at the bottom of the workpiece to raise it, and then use a pressing plate to press the workpiece.

[0003] In the above method of fixing flat workpieces, there is a common technical problem. In order to avoid interference of the pressing plate on the processing, the pads and the pressing plate are usually set at the corners of the workpiece, which makes the middle part of the workpiece suspended. During drilling and tapping, the downward pressure of the cutting tool is likely to cause deformation of the workpiece. Therefore, multiple pads are also required to be distributed at the bottom of the workpiece for support, but it is necessary to avoid the drilling and tapping positions. When the density of the drilling and tapping points is large, it is difficult for the pads to avoid the processing positions, resulting in difficult workpiece clamping or damage to the pads and cutting tools. Therefore, in order to solve the above problems, a machine tool fixture for hardware processing is proposed. Summary of the Invention

[0004] In view of the above or the existing fixtures that use pads to raise the workpiece to provide working space for the cutting tool to penetrate the workpiece, which have problems such as narrow range of use conditions and high operation difficulty and inconvenience, the present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a machine tool fixture for hardware processing.

[0006] To solve the above technical problems, the present invention provides the following technical solution: A machine tool fixture for hardware processing, including an assembly table, and further including a support assembly provided on the assembly table, which includes an outer cylinder with an opening downward. A slideway is provided on the inner wall of the outer cylinder. The path of the slideway is vertical at the bottom and is inserted with a push rod, and is horizontally arc-shaped at the top and slidably sleeved with a ball, and the ball partially protrudes from the inner wall of the outer cylinder. A needle-shaped cylinder is connected between the bottom end of the push rod and the outer cylinder. The top end of the outer cylinder is hermetically and slidably inserted with a short column, and the bottom edge of the short column is pressed against the ball.

[0007] As a preferred scheme of the machine tool fixture for hardware processing of the present invention, wherein: Pressing plates for pressing the workpiece are provided at the four corners of the assembly table, and the support assembly is fixedly inserted on the tabletop of the assembly table, and the top end of the support assembly abuts against the bottom surface of the workpiece.

[0008] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: the slideway is arranged in an arc path around its axis at the top of the outer cylinder, the slideway smoothly transitions from one end of the arc path to a spiral path downward, and the pitch of the spiral path increases downward, the bottom end of the spiral path smoothly transitions to a straight-line path, and the direction of the straight-line path is parallel to the axis direction of the outer cylinder. The axis of the arc of the arc path of the slideway is coaxial with the axis of the outer cylinder. The spiral diameters of all parts of the spiral path of the slideway are equal. A spring is sleeved at the end of the arc path.

[0009] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: the bottom end of the outer cylinder is fixedly inserted with an inner cylinder with an opening downward, and an avoidance groove for a ball is provided on the outer wall of the inner cylinder at the straight-line path of the slideway. The push rod is inserted between the avoidance groove and the straight-line path of the slideway. The outer wall of the cylinder of the needle-shaped cylinder is slidably sleeved with the inner wall of the inner cylinder, and the end of the piston rod of the needle-shaped cylinder is fixedly inserted coaxially with the top end of the inner cylinder. A fixed connection is provided between the bottom end of the cylinder of the needle-shaped cylinder and the bottom end of the push rod.

[0010] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: a first set screw is threadedly fastened along the radial direction between the top end of the inner cylinder and the side wall of the outer cylinder, and the pressing end of the first set screw presses against the side wall of the top end of the piston rod of the needle-shaped cylinder.

[0011] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: an air groove is provided on the outer wall of the inner cylinder parallel to its axis, the air groove penetrates through both ends of the inner cylinder, and a straight-through hole is provided between the inner wall of the top end of the inner cylinder and the air groove.

[0012] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: three pairs of second set screws are arranged in a circular array around the short column at the top end of the outer cylinder, and locking is connected in series between each pair of the second set screws.

[0013] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: a limiting ring is provided on the circumferential wall of the bottom end of the short column and is hooked with the inner wall of the top end of the outer cylinder, and the pressing end of the second set screw penetrates through the top end of the outer cylinder and abuts against the limiting ring.

[0014] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: a cushion block is threadedly fastened to the top end of the short column, and the diameter of the cushion block is larger than the diameter of the short column. A round pin is slidably connected to the outer wall of the short column, and the round pin is inlaid with the inner wall of the outer cylinder.

[0015] As a preferred embodiment of the fixture for a machine tool used in hardware processing according to the present invention, wherein: the support components are distributed in a rectangular array with respect to the assembly table, and parallel pads are vertically and fixedly provided on both bottom surfaces of the assembly table.

[0016] Advantages of the fixture for machine tools used in hardware processing according to the present invention: The present invention is improved on the basis of the existing pressing plate type fixture. By improving the traditional fixed-height spacer block into a support assembly, it can not only provide a reliable support effect with high rigidity for workpiece processing, but also the support assembly corresponding to the processing position can actively and flexibly expand and contract, providing a flexible and safe working space for the tool, greatly improving the operation convenience and flexibility of the traditional pressing plate type fixture. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0018] Figure 1 It is a schematic structural diagram of a fixture for a machine tool used in hardware processing.

[0019] Figure 2 It is Figure 1 A schematic structural diagram from the bottom view.

[0020] Figure 3 It is a structural sectional view of the fixture for a machine tool used in hardware processing at the support assembly.

[0021] Figure 4 It is an exploded structural sectional view of the support assembly.

[0022] Figure 5 It is a structural sectional view of the support assembly.

[0023] Figure 6 It is Figure 5 An enlarged structural view of part A in

[0024] Figure 7 It is Figure 5 A structural sectional view of part B in

[0025] Figure 8 It is a structural sectional view of the outer cylinder at the arc path of the slideway.

[0026] Figure 9 It is an assembled structural sectional view between the needle-shaped cylinder, the inner cylinder and the outer cylinder.

[0027] In the figure: 100, assembly table; 101, pressing plate; 102, parallel backing plate; 200, support assembly; 201, outer cylinder; 202, slideway; 203, push rod; 204, spring; 205, ball; 206, needle-shaped cylinder; 207, short column; 208, limit ring; 209, inner cylinder; 210, clearance groove; 211, air groove; 212, first setscrew; 213, second setscrew; 214, cushion block; 215, round pin; 202a, arc path; 202b, spiral path; 202c, straight path. Detailed implementation mode

[0028] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation mode of the present invention will be given in conjunction with the accompanying drawings of the specification.

[0029] Example, referring to Figures 1 to 9 , this embodiment provides a fixture for a machine tool used in hardware processing. On the basis of the structure of the existing pressing plate 101 type flat workpiece fixture, a large number of support assemblies 200 are arranged in an array to provide a considerable number of support points for workpiece processing, and the active expansion and contraction of the support assemblies 200 corresponding to the processing positions achieve the effect of providing a safe operating space for the tool. As Figure 1 shown, it includes an assembly table 100, and pressing plates 101 for pressing and fixing the workpiece are arranged at the four corners of the assembly table 100. As Figure 2 and Figure 3 shown, the tabletop of the assembly table 100 is fixedly inserted with support assemblies 200, and the tops of the support assemblies 200 abut against the bottom surface of the workpiece; as Figure 4 and Figure 5 shown, the support assembly 200 includes an outer cylinder 201 with an opening downward, a slideway 202 is opened on the inner wall of the outer cylinder 201, the trend of the slideway 202 at the top of the outer cylinder 201 is an arc path 202a, the slideway 202 is smoothly transitioned from one end of the arc path 202a to a spiral path 202b, and the pitch of the spiral path 202b of the slideway 202 gradually increases from top to bottom. The bottom end of the spiral path 202b of the slideway 202 is smoothly transitioned to a straight path 202c, and the direction of the straight path 202c is parallel to the axis direction of the outer cylinder 201. A push rod 203 is inserted into the straight path 202c, and a spring 204 is sleeved at the end of the arc path 202a. The slideway 202 is filled with balls 205 between the spring 204 and the push rod 203, and part of the balls 205 protrudes from the inner wall of the outer cylinder 201. A needle-shaped cylinder 206 is connected between the bottom end of the push rod 203 and the outer cylinder 201. The top end of the outer cylinder 201 is hermetically and slidably inserted with a short column 207, and the bottom edge of the short column 207 is pressed against the balls 205 in the arc path 202a.

[0030] Specifically, as Figure 4As shown, the arc path 202a of the slideway 202 has an axis of the arc coaxial with the axis of the outer cylinder 201. The spiral diameters of the spiral path 202b of the slideway 202 are equal everywhere. The bottom end of the outer cylinder 201 is fixedly inserted with an inner cylinder 209 with an opening downward. And an avoidance groove 210 is provided on the outer wall of the inner cylinder 209 at the straight path 202c of the slideway 202 for fitting the ball 205. The push rod 203 is inserted between the avoidance groove 210 and the straight path 202c of the slideway 202; As Figure 9 shown, the outer wall of the cylinder of the needle-shaped cylinder 206 is slidably sleeved with the inner wall of the inner cylinder 209. And the end of the piston rod of the needle-shaped cylinder 206 is fixedly inserted coaxially with the top end of the inner cylinder 209. A fixed connection is provided between the bottom end of the cylinder of the needle-shaped cylinder 206 and the bottom end of the push rod 203. A first set screw 212 is threadedly fastened along the radial direction between the top end of the inner cylinder 209 and the side wall of the outer cylinder 201. And the pressing end of the first set screw 212 presses against the side wall of the top end of the piston rod of the needle-shaped cylinder 206. An air groove 211 is provided on the outer wall of the inner cylinder 209 parallel to its axis. The air groove 211 penetrates through both ends of the inner cylinder 209. And there is a direct opening connection between the inner wall of the top end of the inner cylinder 209 and the air groove 211.

[0031] As Figure 4 、 Figure 5 and Figure 6 shown, three pairs of second set screws 213 are arranged in a circular array around the short column 207 at the top end of the outer cylinder 201. And each pair of second set screws 213 is connected in series and locked. A limiting ring 208 is provided on the peripheral wall of the bottom end of the short column 207 for hanging connection with the inner wall of the top end of the outer cylinder 201. And the pressing end of the second set screw 213 penetrates through the top end of the outer cylinder 201 to abut against the limiting ring 208; As Figure 2 and Figure 4 shown, a cushion block 214 is threadedly fastened to the top end of the short column 207. And the diameter of the cushion block 214 is larger than the diameter of the short column 207. A round pin 215 is slidably connected to the outer wall of the short column 207. And the round pin 215 is inlaid with the inner wall of the outer cylinder 201. The support assemblies 200 are distributed in a rectangular array with respect to the assembly table 100. Parallel cushion plates 102 are vertically and fixedly provided on both bottom surfaces of the assembly table 100.

[0032] The present invention provides a fixture for a machine tool used in hardware processing, especially a support assembly 200 used in cooperation with a fixture pressing plate 101. When the support assembly 200 works, the short column 207 jacks upward to provide support for the workpiece. The support assembly 200 moves upward while the pressing plate 101 moves downward, so that the fixture clamps the workpiece. And in the working area of the workpiece, the short column 207 of the support assembly 200 actively retracts to provide an operating space for the tool to penetrate the workpiece.

[0033] Therefore, the support assembly 200 also involves the following technical details:

[0034] First, regarding the ejection action and supporting function of the short column 207, when the short column 207 is under a downward pressure after ejection, the ideal state one is to maintain structural rigidity and not cause a retraction due to the downward pressure, resulting in the failure of support. The ideal state two is to have sufficient repeat positioning accuracy, and the height of each rise of the short column 207 needs to be kept consistent;

[0035] First, it is explained how the support assembly 200 maintains structural rigidity after the short column 207 is ejected. Refer to Figure 5 , in this device, the piston rod of the needle-shaped cylinder 206 is fixed relative to the inner cylinder 209 and the outer cylinder 201. The cylinder body of the needle-shaped cylinder 206 drives the push rod 203. The push rod 203 moves upward and pushes the ball 205 deep into the slideway 202, so that the ball 205 slides from the straight path 202c of the slideway 202 through the spiral path 202b and then into the arc path 202a. During the process, the ball 205 pushes up the bottom edge of the short column 207 to lift the short column 207. When the ball 205 enters the arc path 202a, the heights of both the ball 205 and the short column 207 will stop rising. Refer to Figure 8 , when the needle-shaped cylinder 206 reaches the end of its stroke, at this time, the angular range of the ball 205 surrounding the short column 207 in the arc path 202a of the slideway 202 exceeds 200 degrees. When the top of the short column 207 is under pressure, the direction of the extrusion force exerted by the bottom edge of the short column 207 on the ball 205 is perpendicular to the arc path 202a. Therefore, there is no component force in the tangential direction of the arc path 202a, and the ball 205 will not be squeezed back due to the downward pressure of the short column 207. There is a rigid contact between the assembly table 100, the outer cylinder 201, the ball 205, and the short column 207;

[0036] Secondly, it is explained how the support assembly 200 maintains repeat positioning accuracy. Refer to Figure 5 and Figure 6 , there are inevitably dimensional errors and assembly clearances among the ball 205, the slideway 202, and the short column 207. Therefore, fine adjustment needs to be carried out through the second set screw 213. By adjusting the second set screw 213 downward, the second set screw 213 presses the limit ring 208 downward, making the short column 207, the ball 205, and the inner wall of the slideway 202 come into contact, thus initially eliminating the clearance between the short column 207, the ball 205, and the slideway 202. (It should be noted that the pressure of the second set screw 213 on the limit ring 208 should not be too tight to avoid structural locking and inability to move). Then, another second set screw 213 is tightened at the top of the second set screw 213 to achieve the purpose of self-locking and loosening prevention. Each movement of the short column 207 after debugging will be limited by the second set screw 213 and the limit ring 208 to maintain repeat positioning accuracy;

[0037] In addition, in order to further improve the working accuracy of the short column 207, the support assembly 200 also provides a spacer block 214. Refer to Figure 4, the spacer block 214 is used to replace the "sacrificed" short column 207. It not only replaces the worn cross-section of the short column 207, but also allows the machine tool to directly perform a surface milling operation on the top surfaces of all the spacer blocks 214, so as to ensure that the top surfaces of each spacer block 214 are at the same supporting height. There is a technical problem here. The perpendicularity accuracy of the short column 207 is limited. After obtaining a unified height through the "sacrificed" spacer block 214 by surface milling, assuming that the short column 207 is inclined, then once the short column 207 rotates, the top machining surface of the spacer block 214 will not be horizontal. Refer to Figure 5 and Figure 7 , therefore, a positioning round pin 215 is added between the short column 207 and the outer cylinder 201 in the support assembly 200. The main part of the round pin 215 is embedded in the inner wall of the top end of the outer cylinder 201, and a part of the side wall of the round pin 215 protrudes and is slidably connected to the outer wall of the short column 207 along its axis direction, so as to prevent the short column 207 from rotating relative to the outer cylinder 201 and the assembly table 100;

[0038] Second, for the retraction of the short column 207, the structure of the support assembly 200 is very simple and easy to process, use and maintain. There is no elastic element designed specifically for the retraction of the short column 207, but the needle-shaped cylinder 206 is utilized. First, the operation of the needle-shaped cylinder 206 will be described. Refer to Figure 5 and Figure 9 , the needle-shaped cylinder 206 generally has only one air pipe interface, which is located at one end of the cylinder body away from the output shaft. In the support assembly 200, it is located at the bottom end of the support assembly 200. When compressed air is provided to the needle-shaped cylinder 206, the cylinder body of the needle-shaped cylinder 206 is pushed out relative to its piston rod to the bottom of the outer cylinder 201. During this process, the push rod 203 moves downward accordingly, and the spring 204 is reset to push the ball 205 out along the slideway 202 into the arc path 202a. When the ball 205 leaves the arc path and enters the spiral path 202b, the pressure exerted by the short column 207 on the ball 205 downward will further provide assistance for the retraction of the ball 205;

[0039] During the process, there is also a rapid extraction of the needle-shaped cylinder 206 relative to the inner cylinder 209, which will generate a negative pressure between the end of the needle-shaped cylinder 206 and the inner cylinder 209. This negative pressure is connected to the space between the top of the inner cylinder 209, the inner wall of the outer cylinder 201, and the bottom end of the short column 207 through the air groove 211 simply arranged on the side wall of the inner cylinder 209. The short column 207 without the support of the ball 205 is pulled downward by the negative pressure. The resistance of the short column 207 to slide downward without the support of the ball 205 is very small, and it can be easily driven to retract into the outer cylinder 201. In addition, the air groove 211 is also connected to the atmosphere downward. Since the flow area of the air groove 211 is very small, it will not affect the negative pressure to draw back the short column 207. The purpose of connecting the air groove 211 to the atmosphere is that since the moving stroke of the short column 207 is smaller than the moving stroke of the needle-shaped cylinder 206, it is necessary to intake air from the atmosphere after the short column 207 reaches the lower dead point of the stroke to avoid the movement of the needle-shaped cylinder 206 being blocked due to the air resistance formed by the internal seal.

[0040] In summary, the present invention is improved on the basis of the existing pressing plate 101 type fixture. By improving the traditional fixed-height spacer block into the support assembly 200, it can not only provide a reliable support effect with high rigidity for workpiece processing, but also the support assembly 200 corresponding to the processing position can actively and flexibly expand and contract, providing a flexible and safe working space for the tool, greatly improving the operation convenience and flexibility of the traditional pressing plate 101 type fixture.

[0041] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A fixture for a machine tool used in hardware processing, comprising an assembly table (100), characterized in that: It further includes a support assembly (200) disposed on the assembly table (100), which includes an outer cylinder (201) with an opening downward. A slideway (202) is provided on the inner wall of the outer cylinder (201). The path of the slideway (202) is vertical at the bottom and is inserted with a push rod (203), and is horizontally arc-shaped at the top and slidably sleeved with a ball (205). And a part of the ball (205) protrudes from the inner wall of the outer cylinder (201). A needle-shaped cylinder (206) is connected between the bottom end of the push rod (203) and the outer cylinder (201). The top end of the outer cylinder (201) is hermetically and slidably inserted with a short column (207), and the bottom edge of the short column (207) is pressed against the ball (205); The slideway (202) is set as an arc path (202a) around its axis at the top of the outer cylinder (201). The slideway (202) smoothly transitions from one end of the arc path (202a) downward to a spiral path (202b), and the pitch of the spiral path (202b) downward gradually increases. The bottom end of the spiral path (202b) smoothly transitions to a straight path (202c), and the direction of the straight path (202c) is parallel to the axis direction of the outer cylinder (201). For the arc path (202a) of the slideway (202), the axis of the arc is coaxial with the axis of the outer cylinder (201). The spiral diameters of each part of the spiral path (202b) of the slideway (202) are equal. A spring (204) is sleeved at the end of the arc path (202a); The bottom end of the outer cylinder (201) is fixedly inserted with an inner cylinder (209) with an opening downward. And an avoidance groove (210) is provided on the outer wall of the inner cylinder (209) at the straight path (202c) of the slideway (202) to match the ball (205). The push rod (203) is inserted between the avoidance groove (210) and the straight path (202c) of the slideway (202). The outer wall of the cylinder barrel of the needle-shaped cylinder (206) is slidably sleeved with the inner wall of the inner cylinder (209), and the end of the piston rod of the needle-shaped cylinder (206) is fixedly inserted coaxially with the top end of the inner cylinder (209). A fixed connection is provided between the bottom end of the cylinder barrel of the needle-shaped cylinder (206) and the bottom end of the push rod (203); A first set screw (212) is threadedly tightened radially between the top end of the inner cylinder (209) and the side wall of the outer cylinder (201), and the pressing end of the first set screw (212) presses against the side wall of the top end of the piston rod of the needle-shaped cylinder (206); An air groove (211) is provided on the outer wall of the inner cylinder (209) parallel to its axis. The air groove (211) penetrates through both ends of the inner cylinder (209), and there is a direct hole connection between the inner wall of the top end of the inner cylinder (209) and the air groove (211).

2. The fixture for a machine tool used in hardware processing according to claim 1, characterized in that: Pressure plates (101) for pressing the workpiece are provided at the four corners of the assembly table (100), and the support assembly (200) is fixedly inserted on the table surface of the assembly table (100), and the top end of the support assembly (200) abuts against the bottom surface of the workpiece.

3. The fixture for a machine tool used in hardware processing according to claim 1, characterized in that: Three pairs of second setscrews (213) are arranged in an annular array around the short column (207) at the top end of the outer cylinder (201), and each pair of the second setscrews (213) is connected in series and locked.

4. The fixture for a machine tool used in hardware processing according to claim 3, characterized in that: A limiting ring (208) is arranged on the peripheral wall of the bottom end of the short column (207) and is hung on the inner wall of the top end of the outer cylinder (201), and the extrusion end of the second setscrew (213) penetrates through the top end of the outer cylinder (201) and abuts against the limiting ring (208).

5. The fixture for a machine tool used in hardware processing according to claim 4, characterized in that: A cushion block (214) is screwed tightly at the top end of the short column (207), and the diameter of the cushion block (214) is larger than that of the short column (207). A round pin (215) is slidably connected to the outer wall of the short column (207), and the round pin (215) is inlaid with the inner wall of the outer cylinder (201).

6. The fixture for a machine tool used in hardware processing according to claim 1, wherein: The support assemblies (200) are distributed in a rectangular array with respect to the assembly table (100), and parallel cushion plates (102) are vertically and fixedly arranged on both bottom surfaces of the assembly table (100).

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