Feed mechanism

Abstract

To provide a highly reliable feed mechanism that surely suppresses backlash for a long period of time.SOLUTION: A feed mechanism 1 includes: a base 2; a movable body 3; a feed screw 4 rotatably provided on the movable body 3 or the base 2; a support member 20 fixed to the base 2 or the movable body 3 and provided with a first female thread portion with which the feed screw 4 screws; and an axial force generating member 30 including a second female thread portion formed on one side with which the feed screw 4 screws. Biasing means for biasing the axial force generating member 30 in the axial direction is provided between the first female thread portion of the support member 20 and the second female thread portion of the axial force generating member 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a feed mechanism that moves a movable body relative to a base by means of a feed screw. [Background technology]

[0002] Conventionally, a feed mechanism that moves a movable body using a feed screw is disclosed, for example, in Patent Document 1. This feed mechanism includes a base, a movable body, a feed screw that moves the movable body relative to the base, and a torque generating member that has a female thread that screws onto the feed screw, and a housing hole that extends in a direction perpendicular to the feed screw and houses the torque generating member.

[0003] The torque generating member has the role of absorbing backlash between the female screw of the movable body and the feed screw, and is therefore configured so that when an axial force is applied to the movable body, the torque generating member elastically deforms by the amount of backlash. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7407165 Summary of the Invention [Problem to be solved by the invention]

[0005] In the feed mechanism described in the above-mentioned Patent Document 1, the torque generating member is made of an elastic material, has a female thread that screws onto the feed screw, and is configured to be replaceable if its torque generating function deteriorates due to wear over time. Therefore, there is a problem in that the torque generating member must be replaced every time the torque generating function deteriorates and the backlash suppression effect is reduced.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a highly reliable feed mechanism that reliably suppresses backlash over a long period of time. [Means for solving the problem]

[0007] In order to achieve this object, the invention described in claim 1 provides an axial force generating device comprising: a base; a movable body; a feed screw rotatably provided on the movable body or the base; a support member fixed to the base or the movable body and provided with a first female thread portion with which the feed screw screws; and an axial force generating member provided on the support member and having a second female thread portion with which the feed screw screws, the axial force generating member having an axial force generating means between the first female thread portion of the support member and the second female thread portion of the axial force generating member.

[0008] Furthermore, the invention described in claim 2 is characterized in that, in addition to the configuration described in claim 1, the biasing means is provided integrally with the axial force generating member, is formed in a spiral shape, and is configured so that a tip end side comes into contact with an end of the first female thread portion.

[0009] Furthermore, the invention as set forth in claim 3 is characterized in that, in addition to the configuration as set forth in claim 1, a rotation prevention means is provided to prevent the axial force generating member from rotating relative to the support member.

[0010] Furthermore, the invention described in claim 4 is characterized in that, in addition to the configuration described in claim 1, the support member is formed with a storage through-hole extending in the same direction as the axial direction of the feed screw, and the axial force generating member is stored in the storage through-hole. [Effects of the Invention]

[0011] According to the invention of claim 1, a biasing means for biasing the axial force generating member in the axial direction is provided between the first female threaded portion of the support member and the second female threaded portion of the axial force generating member. Therefore, when the feed screw is threaded into the first female threaded portion of the support member, a compressive force is applied to the biasing means to cause elastic deformation while screwing in, thereby biasing the axial force generating member in the axial direction, thereby making it possible to suppress backlash over the long term and improve reliability.

[0012] Furthermore, according to the invention described in claim 2, the biasing means is provided integrally with the axial force generating member, is formed in a spiral shape, and is configured so that its tip end side abuts against the end of the first female thread portion, thereby improving reliability over a long period of time.

[0013] According to the invention recited in claim 3, since anti-rotation means is provided for preventing the axial force generating member from rotating relative to the support member, it is possible to reliably prevent the axial force generating member from rotating, thereby further improving the reliability of the feed mechanism.

[0014] Furthermore, according to the invention described in claim 4, a storage through-hole extending in the same direction as the axial direction of the feed screw is formed in the support member, and the axial force generating member is stored in this storage through-hole, thereby making it possible to reduce the size of the entire feed mechanism. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing an embodiment of a feed mechanism according to the present invention; [Figure 2] 2 is a perspective view of the feed mechanism of FIG. 1, seen from a different direction. [Figure 3] FIG. 2 is a plan view showing the feed mechanism of FIG. [Figure 4] 4 is an enlarged plan view showing the support member, the feed screw, and the axial force generating member of FIG. 3. [Figure 5] FIG. 2 is a front view showing the feed mechanism of FIG. [Figure 6] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 7]FIG. 5 is an enlarged perspective view showing the axial force generating member of FIG. 4. [Figure 8] FIG. 7 is an enlarged cross-sectional view showing a state in which the axial force generating member of FIG. 6 is attached to a support member. [Figure 9] FIG. 10 is a perspective view showing a first modified example of an axial force generating member in an embodiment of a feed mechanism according to the present invention. [Figure 10] FIG. 10 is a perspective view showing a second modified example of an axial force generating member in the embodiment of the feed mechanism according to the present invention. [Figure 11] 1 is a perspective view showing an application example of an embodiment of a feed mechanism according to the present invention. [Figure 12] FIG. 12 is a vertical cross-sectional view showing an application example of FIG. [Figure 13] FIG. 12 is an enlarged perspective view showing an axial force generating member in the application example of FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of a feed mechanism according to the present invention will be described below.

[0017] (One embodiment of the feeding mechanism) Fig. 1 is a perspective view showing one embodiment of a feed mechanism according to the present invention. Fig. 2 is a perspective view of the feed mechanism of Fig. 1 seen from a different direction. Fig. 3 is a plan view showing the feed mechanism of Fig. 1. Fig. 4 is an enlarged plan view showing a support member, a feed screw, and an axial force generating member of Fig. 3. Fig. 5 is a front view showing the feed mechanism of Fig. 1. Fig. 6 is a cross-sectional view taken along line AA of Fig. 3.

[0018] 1 to 6, the feed mechanism 1 of this embodiment includes a base 2, a movable body 3, a feed screw 4, a connecting member 10, a support member 20, and an axial force generating member 30. The feed mechanism 1 is also called a table device, a stage device, or the like.

[0019] The base 2 is formed in the shape of a rectangular flat plate in a plan view. The planar shape of the base 2 is not particularly limited to a rectangular shape and may be other shapes. The base 2 is attached to a fixed member such as a frame (not shown), and is formed with mounting holes (not shown) for fastening to the fixed member with fastening members such as bolts. The material of the base 2 is not particularly limited, and may be a material with high rigidity and durability, such as metals such as aluminum, copper, brass, iron, nickel, magnesium, and tungsten, or polymer resins.

[0020] A guide mechanism (not shown) is attached to the top surface of the base 2 to guide the linear movement of the movable body 3 relative to the base 2. This guide mechanism may be, for example, a cross roller guide or a linear guide, and in this embodiment, a cross roller guide is used as an example. However, this embodiment is not particularly limited to these guide mechanisms.

[0021] Here, the cross roller guide is composed of two guide rail sets, each consisting of a plurality of guide rollers, a plate-shaped retainer for holding these guide rollers rotatably, and a pair of rectangular guide rails arranged in parallel on either side of the guide rollers and retainer.

[0022] The feed screw 4 is rotatably supported on one side of the movable body 3 via a connecting member 10. A male thread portion 5 is formed on the feed screw 4 along substantially the entire length in the axial direction. The type of thread of this male thread portion 5 is not particularly limited, and it may be a triangular thread or a trapezoidal thread. One end of the feed screw 4 is provided with a head 6 so that the feed screw 4 can be rotated using a tool such as a hex wrench or manually. In this case, the feed screw 4 may be rotated using a screwdriver other than a hex wrench, or the feed screw 4 may be configured to rotate automatically using a motor. The material of the feed screw 4 is not particularly limited, and a metal such as steel is used, for example.

[0023] The connecting member 10 is formed by a metal fitting that is L-shaped in plan view, and includes a fixed piece 11 that is fixed to one side of the movable body 3 by a fastening member, and a protruding piece 12 that protrudes perpendicularly outward from the fixed piece 11. A circular insertion hole 13 is formed in the protruding piece 12, and the male thread portion 5 near the head 6 of the feed screw 4 is rotatably inserted into this insertion hole 13.

[0024] A nut 7 is threaded onto the male thread portion 5 near the head 6 of the feed screw 4. In this embodiment, the position of the movable body 3 relative to the base 2 is adjusted by rotating the feed screw 4, and then the threaded position of the nut 7 relative to the male thread portion 5 is moved to sandwich the protruding piece 12 between the head 6 of the feed screw 4, thereby reliably preventing the feed screw 4 from rotating.

[0025] The movable body 3 is formed in the shape of a rectangular flat plate whose length and width dimensions in plan view are the same as those of the base 2. The material of the movable body 3 is not particularly limited, and may be, for example, a metal such as aluminum, or a resin. As described above, the linear movement of the movable body 3 is guided by the cross roller guide attached to the upper surface of the base 2.

[0026] The movable body 3 is provided with, for example, a precision vise. Specifically, a tool used in the field of machine tools is provided and is used to fix materials in machining processes using milling, drilling, grinding, etc. In addition to a precision vise, an optical accessory may also be provided on the movable body 3. Specifically, a device or tool used in optical technology is provided and is used in equipment that precisely positions mirrors and lenses to control the optical axis of a laser beam or the like. Note that the member provided on the movable body 3 can be any member that requires precise positioning.

[0027] Fig. 7 is an enlarged perspective view showing the axial force generating member of Fig. 4. Fig. 8 is an enlarged sectional view showing the axial force generating member of Fig. 6 attached to a support member.

[0028] A support member 20 is fixed to one side surface of the base 2, which is the same side surface as the side surface of the movable body 3 to which the connecting member 10 is fixed. This support member 20 is integrally formed with a fixed portion 21 that is fixed to one side surface of the base 2 by a fastening member, and a storage portion 22 that is provided so as to protrude outward from this fixed portion 21. A storage through-hole 23 is formed inside this storage portion 22, extending in the same direction as the axial direction of the feed screw 4, as shown in Figures 6 and 8. This storage through-hole 23 has a circular cross section and is formed so as to penetrate through the storage portion 22 in the lengthwise direction.

[0029] 8, a female thread portion (first female thread portion) 24 into which the male thread portion 5 of the feed screw 4 is threaded is formed at the tip of the insertion side of the feed screw 4 in the storage through-hole 23. The type of this female thread portion 24 is not particularly limited, and like the feed screw 4, it may be a triangular thread, a trapezoidal thread, or the like.

[0030] As shown in Figures 1 and 4, the support member 20 has a single elongated pin insertion hole 25 that penetrates the side surface at the upper part of the side surface of the insertion side tip of the feed screw 4, and is configured so that an elongated fixing pin 26 can be inserted into this pin insertion hole 25.

[0031] Furthermore, the axial force generating member 30 is inserted into the housing through-hole 23 until the tip end side thereof abuts against the end of the female thread portion 24. The material of the axial force generating member 30 is the same as the material of the base 2 and is not particularly limited, and materials with high rigidity and durability, such as metals such as aluminum, copper, brass, iron, nickel, magnesium, and tungsten, and polymer resins, are used.

[0032] The outer diameter of the axial force generating member 30 is larger than the diameter of the male thread portion 4 of the feed screw 4 and smaller than the diameter of the housing through-hole 23. As shown in Figures 4 and 7, the axial force generating member 30 is provided with a square spring 32 formed in a spiral shape as a biasing means in the axial center portion. The axial force generating member 30 has four pin insertion holes 33 formed at regular intervals (90-degree intervals in this embodiment) in the circumferential direction on the tip surface in the insertion direction.

[0033] The axial force generating member 30 has a female thread portion (second female thread portion) 34 formed on the inner peripheral surface on the rear end side in the insertion direction. The female thread portion 34 is not formed in the area of ​​the square spring 32. In this way, the axial force generating member 30 is formed so as to be elastically deformable in the axial direction by the square spring 32.

[0034] Next, the operation of the feed mechanism 1 of this embodiment will be described.

[0035] First, the nut 7 is screwed onto the male thread portion 5 of the feed screw 4, and then the axial force generating member 30 is screwed onto the male thread portion 5 of the feed screw 4. In this state, the axial force generating member 30 is stored in the storage through-hole 23 until the tip end side of the axial force generating member 30 abuts against the female thread portion 24 of the support member 20.

[0036] At this time, by screwing the male thread portion 5 of the feed screw 4 into the female thread portion 24 of the support member 20 while applying an appropriate pressure to the housing through-hole 23 of the support member 20 so that the square spring 32 of the axial force generating member 30 contracts in the axial direction, the square spring 32 is elastically deformed, and as shown in Figure 8, an axial force F can be continuously generated between the female thread portion 24 of the support member 20 and the female thread portion 34 of the axial force generating member 30.

[0037] Next, one pin insertion hole 25 of the support member 20 is aligned in the circumferential direction with one of the four pin insertion holes 33 on the insertion-side tip face of the axial force generating member 30. That is, alignment is performed so that the pin insertion hole 25 of the support member 20 communicates with the pin insertion hole 33 of the axial force generating member 30, and by inserting a fixing pin 26 successively through these pin insertion holes 25, 33, movement of the axial force generating member 30 in the rotational direction can be reliably prevented.

[0038] 8, the female thread portion 24 of the support member 20 and the female thread portion 34 of the axial force generating member 30 are pressed against the threads of the male thread portion 5 of the lead screw 4 by the biasing force of the square spring 32, so that they come into close contact with each other without any gaps. Specifically, when the lead screw 4 is rotated relative to the female thread portion 24 of the support member 20 and the female thread portion 34 of the axial force generating member 30, the square spring 32 of the axial force generating member 30 continuously generates an axial force F that resists the rotation of the lead screw 4.

[0039] Therefore, in this embodiment, when the lead screw 4 is manually rotated, the axial force generating member 30 prevents rattle of the lead screw 4 and allows the lead screw 4 to be screwed in smoothly, thereby enabling the lead screw 4 to be fed with high precision. As a result, after the position of the movable body 3 is adjusted, movement of the movable body 3 can be prevented in advance.

[0040] The axial force generating member 30 prevents backlash between the female thread portions 24, 34 and the male thread portion 5 of the feed screw 4. In other words, the axial force generating member 30 has the function of preventing rattle of the movable body 3 caused by backlash. The position of the movable body 3 is determined by the female thread portion 34, which fits tightly against the feed screw 4.

[0041] As described above, according to this embodiment, the square spring 32 that urges the axial force generating member 30 in the axial direction is provided between the female thread portion 24 of the support member 20 and the female thread portion 34 of the axial force generating member 30. Therefore, when the feed screw 4 is screwed into the female thread portion 24 of the support member 20, the square spring 32 is screwed in while applying a compressive force to the square spring 32, thereby urging the axial force generating member 30 in the axial direction, thereby suppressing backlash over the long term and improving reliability.

[0042] Furthermore, according to this embodiment, the square spring 32 is provided integrally with the axial force generating member 30, is formed in a spiral shape, and is configured so that its tip end abuts against the end of the female thread portion 24, thereby improving reliability over the long term.

[0043] Furthermore, according to this embodiment, the fixing pin 26 is provided as anti-rotation means for preventing the axial force generating member 30 from rotating relative to the support member 20. The fixing pin 26 is inserted into the pin insertion hole 25 of the support member 20 and the pin insertion hole 33 of the axial force generating member 30. This reliably prevents the axial force generating member 30 from moving in the rotational direction, thereby enhancing the backlash prevention effect.

[0044] Furthermore, according to the present embodiment, the support member 20 is formed with a storage through-hole 23 extending in the same direction as the axial direction of the feed screw 4, and the axial force generating member 30 is stored in this storage through-hole 23, thereby making it possible to reduce the size of the entire feed mechanism 1.

[0045] (First Modification of Axial Force Generating Member) 9 is a perspective view showing a first modified example of an axial force generating member in one embodiment of the feed mechanism according to the present invention. In this modified example, parts that are the same as or correspond to those in the above embodiment are denoted by the same reference numerals. The same applies to other modified examples and application examples.

[0046] 9, an axial force generating member 30A of this modification uses a wave spring 35 as a biasing means, instead of the square spring 32 of the above embodiment. The wave spring 35 has a low extension / contraction direction, i.e., a low height as a spring, and is formed by winding a plate-shaped steel wire in a spiral or annular shape to create a wave shape. Although the wave spring 35 has the same spring force as a conventional round wire coil spring, it is space-saving and lightweight, and can also be used for vibration absorption purposes.

[0047] Pin insertion holes 33, through which fixing pins (not shown) are inserted as anti-rotation means, are formed on both axial sides of the wave spring 35. These pin insertion holes 33 are arranged at 90-degree intervals in the circumferential direction, as in the above embodiment.

[0048] As in the previous embodiment, the axial force generating member 30A has a cylindrical portion 36 on the rear end side in the insertion direction, which has a female thread portion (second female thread portion) 34 formed on the inner peripheral surface thereof. The cylindrical portion 36 is continuous with the wave spring 35. The cylindrical portion 36 is made of a highly rigid and durable material such as a metal, such as aluminum, copper, brass, iron, nickel, magnesium, or tungsten, or a polymeric resin. The cylindrical portion 36 and the wave spring 35 may be fixed by a fixing pin (not shown) or by adhesive. In this way, the axial force generating member 30A is formed to be elastically deformable in the axial direction by the wave spring 35.

[0049] As described above, according to this modification, the wave spring 35 is used as the biasing means, and thus a biasing force equivalent to that of a coil spring can be obtained over a small span, allowing the biasing member to be housed in a small space. This prevents the axial force generating member 30A from becoming too large and also reduces costs.

[0050] In this modified example, the pin insertion hole 33 through which the fixing pin is inserted is formed as the anti-rotation means, but the present invention is not limited to this, and the function of the anti-rotation means may be realized by fixing with adhesive, for example. The other configurations and functions are the same as those of the above embodiment, and therefore the description thereof will be omitted.

[0051] (Second Modification of Axial Force Generating Member) FIG. 10 is a perspective view showing a second modified example of an axial force generating member in an embodiment of the feed mechanism according to the present invention.

[0052] As shown in Fig. 10, an axial force generating member 30B of this modified example is provided with a cylindrical rubber 37 as a biasing means instead of the square spring 32 of the above embodiment. This cylindrical rubber 37 is fixed between the left and right cylindrical portions 36a, 36b. The cylindrical rubber 37 and the left and right cylindrical portions 36a, 36b may be prevented from rotating by a fixing pin and a pin insertion hole as in the first modified example, or may be fixed with an adhesive.

[0053] The left and right cylindrical portions 36a, 36b may be made of the same material as the cylindrical portion 36 of the first modified example. Note that the axial force generating member 30B of this modified example has a female thread portion 34 formed as a second female thread portion on the inner circumferential surface of the cylindrical portion 36b. The left and right cylindrical portions 36a, 36b and the cylindrical rubber 37 are in axial communication with each other so that the male thread portion 5 is inserted therethrough. In this way, the axial force generating member 30B is formed by the cylindrical rubber 37 so as to be elastically deformable in the axial direction.

[0054] Therefore, according to this modification, the cylindrical rubber 37 is used as the biasing means, which makes it possible to easily attach the cylindrical rubber 37 and reduce costs. The other configurations and operations are the same as those of the above embodiment, so a description thereof will be omitted.

[0055] (Example of application of feed mechanism) Fig. 11 is a perspective view showing an application example of one embodiment of a feed mechanism according to the present invention. Fig. 12 is a longitudinal sectional view showing the application example of Fig. 11. Fig. 13 is an enlarged perspective view showing an axial force generating member in the application example of Fig. 11. This application example is an example of application to an optical accessory, more specifically, an example of application to an angle adjustment mechanism for a lens holder.

[0056] 11, feed mechanisms 1A in this application example are provided at the upper and lower corners of the base 2. These feed mechanisms 1A are respectively provided in the housing through-holes 23 of the support members 20 of the base 2. A rotatable body 3A is attached to the tip of the feed screw 4 of the feed mechanism 1A via a connecting part 8 so that the angle can be adjusted relative to the base 2. The angle of this rotatable body 3A is adjusted around a rotation part fulcrum 41.

[0057] A female thread portion (first female thread portion) 24 is formed on the rear end side of the storage through-hole 23 of the support member 20 in the insertion direction of the feed screw 4. A male thread portion 38 of the axial force generating member 30C is screwed into this female thread portion 24, thereby fixing the axial force generating member 30C to the storage through-hole 23 of the support member 20.

[0058] As shown in FIGS. 12 and 13, the axial force generating member 30C is formed as a single unit, with a flange portion 39 formed continuous with the male thread portion 38, and a square spring 32 serving as a biasing means formed continuous with this flange portion 39.

[0059] The axial force generating member 30C has an insertion hole 40, through which the feed screw 4 is inserted, formed in its axial core so as to communicate in the axial direction. Within this insertion hole 40, a female thread portion (first female thread portion) 41 is formed at the position where the male thread portion 38 is formed, and a female thread portion (second female thread portion) 42 is formed at the position where the square spring 32 is formed. No female thread portion is formed between these female thread portions 41, 42. In other words, no female thread portion is formed within the insertion hole 40 where the flange portion 39 is formed.

[0060] Next, the operation of the feed mechanism 1A of this application example will be described.

[0061] First, the axial force generating member 30C is screwed onto the male thread portion 5 of the feed screw 4 up to the vicinity of the head 6, and then the male thread portion 38 of the axial force generating member 30C is screwed onto the female thread portion 24 of the support member 20. Then, the rotatable body 3A is connected to the tip end of the male thread portion 5 of the feed screw 4 via the connecting portion 8.

[0062] Furthermore, the head 6 of the feed screw 4 is rotated to screw the male threaded portion 5 into the female threaded portion 24 until the front side of the flange portion 39 abuts against the open end surface of the housing through-hole 23 of the support member 20. At this time, by screwing the male threaded portion 5 of the feed screw 4 into the female threaded portion 34 of the axial force generating member 30C while applying an appropriate pressure so that the square spring 32 of the axial force generating member 30C contracts in the axial direction, the square spring 32 is elastically deformed, and it is possible to constantly and continuously generate an axial force F between the female threaded portion 24 of the support member 20 and the female threaded portion 34 of the axial force generating member 30C.

[0063] The female thread portion 24 of the support member 20 and the female thread portion 34 of the axial force generating member 30 are pressed against the threads of the male thread portion 5 of the feed screw 4 by the biasing force of the square spring 32, so that they come into close contact with each other without any gaps. Specifically, when the feed screw 4 is rotated relative to the female thread portion 24 of the support member 20 and the female thread portion 34 of the axial force generating member 30C, an axial force F that resists the rotation of the feed screw 4 is continuously generated by the square spring 32 of the axial force generating member 30C.

[0064] Therefore, in this embodiment, when the lead screw 4 is manually rotated, the axial force generating member 30 prevents rattle of the lead screw 4 and allows the lead screw 4 to be screwed in smoothly, thereby enabling the lead screw 4 to be fed with high precision. As a result, after the position of the rotatable body 3A is adjusted, movement of the rotatable body 3A can be prevented in advance. The other configurations and operations are the same as those of the above embodiment, and therefore description thereof will be omitted.

[0065] [Another embodiment of the invention] Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be embodied in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. This embodiment and its modifications are included within the scope and spirit of the invention, as well as the invention described in the claims and their equivalents.

[0066] For example, in the above embodiment, an example was described in which a square spring 32 was used as the biasing means, but of course a round spring may also be used, and multiple biasing means such as coil springs or leaf springs may also be arranged circumferentially between the cylindrical portion having the pin insertion hole 33 and the cylindrical portion having the female thread portion 34.

[0067] In the above embodiment, the rotation preventing means for preventing the axial force generating member 30 from rotating relative to the support member 20 is the fixing pin 26 inserted through the pin insertion hole 25 of the support member 20 and the pin insertion hole 33 of the axial force generating member 30, but this is not limiting and, for example, a recess may be formed on the abutting surface of the axial force generating member 30 of the support member 20, and a protrusion that fits into this recess may be formed on the axial force generating member 30.

[0068] Furthermore, in the above embodiment, an example was described in which the length and width dimensions of the movable body 3 were formed to be the same as those of the base 2, but this is not limited to this and the movable body 3 and the base 2 may be formed to have different length and width dimensions from each other.

[0069] In the above embodiment, an example has been described in which the feed screw 4 is provided to the movable body 3 via the connecting member 10, while the support member 20 is fixed to the base 2, but conversely, the feed screw 4 may be provided to the base 2 via the connecting member 10, while the support member 20 is fixed to the movable body 3. Even with this configuration, the same effects as in the above embodiment can be obtained. [Explanation of symbols]

[0070] 1. Feed mechanism 1A Feed mechanism 2. Bass 3 Movable body 3A Rotating Movable Body 4 Lead Screw 5 Male thread 6 head 7 Nuts 10 Connecting member 11 Fixed piece 12 Overhang piece 13 Insertion hole 20 Support member 21 Fixed part 22 Storage area 23 Storage through hole 24 Female thread portion (first female thread portion) 25 Pin insertion hole (anti-rotation means) 26 Fixing pin (anti-rotation means) 30 Axial force generating member 30A Axial force generating member 30B Axial force generating member 30C Axial force generating member 32 Square spring (biasing means) 33 Pin insertion hole (anti-rotation means) 34 Female thread portion (second female thread portion) 35 Wave spring (biasing means) 36 Cylindrical part 36a, 36b cylindrical part 37 Cylindrical rubber (biasing means) 38 Male thread 39 Flange 40 Insertion hole

Claims

1. With the base, A movable body and a feed screw rotatably provided on the movable body or the base; a support member fixed to the base or the movable body and provided with a first female screw portion into which the feed screw is threaded; an axial force generating member having a second female thread portion formed on one side thereof with which the feed screw is threadedly engaged, a biasing means for biasing the axial force generating member in the axial direction, the biasing means being provided between the first female threaded portion of the support member and the second female threaded portion of the axial force generating member.

2. 2. The feed mechanism according to claim 1, wherein the biasing means is provided integrally with the axial force generating member, is formed in a spiral shape, and has a tip end side that abuts against an end of the first female thread portion.

3. 2. The feed mechanism according to claim 1, further comprising a rotation preventing means for preventing the axial force generating member from rotating relative to the support member.

4. 2. The feed mechanism according to claim 1, wherein the support member is formed with a housing through-hole extending in the same direction as the axial direction of the feed screw, and the axial force generating member is housed in the housing through-hole.

Images