Units and optical instruments

Abstract

This technology offers advantages in suppressing the seepage and spread of lubricating fluid. [Solution] One of the first and second parts is movable relative to the other, and a lubricant is placed between the first and second parts. The first surface of the first part has a first region, a second region and a third region, the first region is slidable to the second part via the lubricant, the second region is placed between the first and third regions, the second region has an uneven structure composed of a plurality of protrusions and / or a plurality of recesses, the distance between two adjacent protrusions and / or the distance between two adjacent recesses is 80 μm or less, the height of each of the plurality of protrusions and / or the depth of each of the plurality of recesses is 1 μm or more, the width of each of the plurality of protrusions and / or the width of each of the plurality of recesses is 100 μm or less, and the arithmetic mean roughness of the third region at a reference length of 700 μm is 0.01 μm or more and 0.55 μm or less.

Description

Technical Field

[0001] The present disclosure relates to units and optical devices.

Background Art

[0002] Many products such as optical devices are composed of multiple parts. The multiple parts include a first part and a second part where one is movable relative to the other. A gap is provided between the first part and the second part so that one of the first part and the second part can move smoothly relative to the other. In order to suppress the friction and wear due to the friction between the first part and the second part, a lubricating fluid such as grease or oil is disposed in the gap between the first part and the second part. Patent Document 1 discloses a configuration in which lubricating oil is applied between the surface of an operating member and the surface of a fixed member so that smooth rotation can be performed in a lens barrel in which the operating member is rotatable about the optical axis with respect to the fixed member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional configuration, there is a risk that the lubricating fluid may seep and spread.

Means for Solving the Problems

[0005] One of the objectives of the present disclosure is to provide a technology that is advantageous for suppressing the seepage and spread of the lubricating fluid.

[0006] A first aspect of the present disclosure is a unit comprising a first part and a second part, wherein one of the first part and the second part is movable relative to the other, and a lubricant is disposed between the first part and the second part, wherein the first surface of the first part has a first region, a second region and a third region, the first region is slidable toward the second part via the lubricant, the second region is disposed between the first region and the third region along the first surface, and the second region is an uneven surface composed of a plurality of protrusions and / or a plurality of recesses The unit is characterized by having a structure in which the distance between two adjacent protrusions and / or the distance between two adjacent recesses is 80 μm or less, the height of each of the multiple protrusions and / or the depth of each of the multiple recesses of the uneven structure is 1 μm or more, the width of each of the multiple protrusions and / or the width of each of the multiple recesses of the uneven structure is 100 μm or less, and the arithmetic mean roughness at a reference length of 700 μm of the third region is 0.01 μm or more and 0.55 μm or less.

[0007] A second aspect of the present disclosure is a unit comprising a first part and a second part, wherein one of the first part and the second part is movable relative to the other, and a lubricant is disposed between the first part and the second part, wherein the first surface of the first part has a first region, a second region, a third region and a fourth region, the first region is slidable toward the second part via the lubricant, the second region is disposed along the first surface between the first region and the third region, the fourth region is disposed between the first region and the second region, the second region has an uneven structure composed of a plurality of protrusions and / or a plurality of recesses, the arithmetic mean roughness of the third region at a reference length of 700 μm is smaller than the arithmetic mean roughness of the second region at a reference length of 700 μm, and the arithmetic mean roughness of the fourth region at a reference length of 700 μm is smaller than the arithmetic mean roughness of the second region and larger than the arithmetic mean roughness of the first region. [Effects of the Invention]

[0008] This disclosure provides a technology that is advantageous for suppressing the seepage and spread of lubricating fluid. [Brief explanation of the drawing]

[0009] [Figure 1] (a) and (b) are explanatory diagrams of a part of the unit according to the first embodiment. [Figure 2] This is a cross-sectional view of the unit according to the first embodiment. [Figure 3] This is an enlarged perspective view showing a portion of the outer surface of a component according to the first embodiment. [Figure 4] (a) is an explanatory diagram of the uneven structure according to the first embodiment. (b) to (f) are explanatory diagrams of the uneven structure according to a modified example of the first embodiment. [Figure 5] (a) and (b) are explanatory diagrams of a part of the uneven structure region and a part of the smooth surface region according to the first embodiment. [Figure 6] (a) is an explanatory diagram of a part of the uneven structure region and a part of the smooth surface region according to the first embodiment. (b) is an explanatory diagram of a part of the uneven structure region and a part of the smooth surface region according to a modified example of the first embodiment. [Figure 7] This figure shows the results of the sealing performance of the lubricating fluid when the distance between the two protrusions according to the first embodiment is changed. [Figure 8] (a) and (b) are cross-sectional views of a portion of the uneven structure region according to the first embodiment. [Figure 9] This figure shows the results of the sealing performance of the lubricating fluid when the arithmetic mean roughness of the smooth surface region according to the first embodiment is changed. [Figure 10] (a) and (b) are cross-sectional views of a portion of the uneven structure region according to the first embodiment. [Figure 11] This is an enlarged perspective view showing a portion of the outer surface of part 1 according to the second embodiment. [Figure 12] This is an enlarged perspective view showing a portion of the outer surface of a part relating to a comparative example. [Figure 13] (a) is an enlarged perspective view of a part of the outer surface of the component according to the third embodiment. (b) is an enlarged plan view of a part of the outer surface of the component according to the third embodiment. [Figure 14] (a) to (e) are diagrams schematically showing the injection molding process for manufacturing the resin molded product according to the third embodiment. [Figure 15] (a) is a photograph of a part of the surface of the mold according to the third embodiment observed with a scanning electron microscope. (b) is a photograph of the uneven structure region of the part according to the third embodiment observed with an electron microscope. [Figure 16] (a) is a schematic perspective view showing a configuration example of the laser processing machine according to the third embodiment. (b) is an enlarged view showing the state of processing performed on the surface of the base material by the laser processing machine according to the third embodiment. [Figure 17] It is a schematic perspective view of the imaging device according to the fourth embodiment. [Figure 18] (a) is a perspective view of a unit that is a part of the lens barrel according to the fourth embodiment. (b) is a perspective view of the part according to the fourth embodiment. [Figure 19] It is an enlarged perspective view of the part according to the fourth embodiment. [Figure 20] It is a schematic perspective view of a part of the part according to the example.

Mode for Carrying Out the Invention

[0010] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments shown below are examples, and for example, those skilled in the art can appropriately change and implement the details of the configuration without departing from the spirit of the present invention.

[0011] In the drawings referred to in the following description of the embodiments, unless otherwise specified, elements denoted by the same reference numerals have the same functions. In the drawings, when a plurality of the same elements are arranged, the assignment of reference numerals and their descriptions may be omitted. Also, for the convenience of illustration and explanation, the drawings may be schematically represented, so the shapes, sizes, and arrangements of the elements shown in the drawings do not necessarily exactly match the elements shown in other drawings and actual objects.

[0012] <First Embodiment> Figures 1(a) and 1(b) are explanatory diagrams of a part of unit 100 according to the first embodiment. Unit 100 has a generally cylindrical shape. Unit 100 comprises part 1 and part 2. Part 1 and part 2 are engaged with each other such that one of them is movable relative to the other. Figure 1(a) shows part 1 and part 2 engaged with each other. Figure 1(b) shows part 1 and part 2 separated from each other for the sake of explanation. As shown in Figure 1(a), a part 51 of part 1 and a part 52 of part 2 face each other. A gap 3 is provided between part 51 of part 1 and part 52 of part 2, and a lubricating fluid 12 such as grease or oil is placed in the gap 3.

[0013] Part 1 and Part 2 are cylindrical parts. One of Part 1 and Part 2 is rotatable relative to the other in the circumferential direction R1 of Unit 100. One of Part 1 and Part 2 is, for example, Part 2, and the other of Part 1 and Part 2 is, for example, Part 1. The circumferential direction R1 is the direction of rotation of Part 1 and Part 2 around the rotation axis C1. The rotation axis C1 is the axis (central axis) that indicates the center of rotation of Part 1 and Part 2.

[0014] The material of part 1 and part 2 is preferably resin, but may also be metal, ceramic, or other materials. In the first embodiment, the material of part 1 and part 2 is polycarbonate. Parts 1 and 2 are typically injection-molded resin products (injection molded articles).

[0015] Component 1 has an outer surface 101 and an inner surface 102, and component 2 has an outer surface 104 and an inner surface 103. The inner surface 102 is the surface opposite to the outer surface 101. The outer surface 104 is the surface opposite to the inner surface 103. The outer surface 101 can also be called the front surface and the inner surface 102 the back surface, or the inner surface 103 can be called the front surface and the outer surface 104 the back surface. When components 1 and 2 are injection molded products, they are formed by injecting molten resin into a cavity defined by a movable mold and a fixed mold as the molding die. Typically, the outer surface 101 of component 1 is molded on one of the movable mold and the fixed mold, and the inner surface 102 of component 1 is molded on the other of the movable mold and the fixed mold. Typically, the inner surface 103 of component 2 is molded on one of the movable mold and the fixed mold, and the outer surface 104 of component 2 is molded on the other of the movable mold and the fixed mold.

[0016] The outer surface 101 of part 1 has an outer region 161 that is exposed to the outside of unit 100. The inner surface 103 of part 2 has an inner region 162 that is exposed to the inside of unit 100. Each of the outer region 161 of part 1 and the outer surface 104 of part 2 is part of the outer surface of unit 100. Each of the inner surface 102 of part 1 and the inner region 162 of part 2 is part of the inner surface of unit 100.

[0017] In the first embodiment, a portion 51 of part 1 has faces 4, 5, and 6. Faces 4 and 5 are part of the outer surface 101 of part 1, and face 6 is an end face that connects the outer surface 101 and the inner surface 102 of part 1. Face 5, which connects to faces 4 and 6, is located between face 4 and face 6. Burrs may be present on the end face due to the parting line of the mold in injection molding. In addition to the parting line between the movable mold and the fixed mold, there may also be parting lines between parts when the movable mold or fixed mold is composed of multiple parts.

[0018] Furthermore, in the first embodiment, a portion 52 of part 2 has faces 7, 8, and 9. Faces 9 and 8 are part of the inner surface 103 of part 2, and face 7 is an end face that connects the outer surface 104 and the inner surface 103 of part 2. Face 8, which connects to faces 7 and 9, is positioned between face 7 and face 9. Face 4 faces face 7, face 5 faces face 8, and face 6 faces face 9. Of the outer surface 101 of part 1, the portions other than faces 4 and 5 do not face part 2. Of the inner surface 103 of part 2, the portions other than faces 8 and 9 do not face part 1.

[0019] In the first embodiment, part 1 is an example of a first part, and part 2 is an example of a second part. Also in the first embodiment, the outer surface 101 of part 1 is an example of a first surface, the inner surface 102 of part 1 is an example of a second surface, the inner surface 103 of part 2 is an example of a third surface, and the outer surface 104 of part 2 is an example of a fourth surface.

[0020] Figure 2 is a cross-sectional view of unit 100 according to the first embodiment. Figure 2 shows a cross-section of the area enclosed by circle A1 shown in Figure 1(a).

[0021] As shown in Figure 2, the surface 5 of part 1 has a sliding region 111. The sliding region 111 is an example of a first region. The sliding region 111 is a band-shaped region extending in the circumferential direction R1. The sliding region 111 of part 1 is slidable relative to part 2 via the lubricating fluid 12.

[0022] Furthermore, surface 5 of part 1 has an intermediate region 141, an uneven structure region 121, and a smooth surface region 131. Each of the intermediate region 141, the uneven structure region 121, and the smooth surface region 131 is a band-shaped region extending in the circumferential direction R1. The uneven structure region 121 is an example of a second region, the smooth surface region 131 is an example of a third region, and the intermediate region 141 is an example of a fourth region.

[0023] In the gap 3, the intermediate region 141, the uneven structure region 121, and the smooth surface region 131 are arranged in this order along the outer surface 101 in the direction from the sliding region 111 toward the outside of the unit 100. That is, the uneven structure region 121 is located along the outer surface 101 between the sliding region 111 and the smooth surface region 131. The intermediate region 141 is located along the outer surface 101 between the sliding region 111 and the uneven structure region 121.

[0024] The inner surface 103 (surface 8) of part 2 faces the sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131 of part 1. That is, the sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131 of part 1 overlap the inner surface 103 (surface 8) of part 2 in a direction perpendicular to the rotation axis C1. Also, the outer region 161 of part 1 is exposed to the outside in unit 100. Therefore, the outer region 161 of part 1 does not face the inner surface 103 of part 2.

[0025] Furthermore, the surface 8 of part 2 has a sliding region 112. The sliding region 112 is a band-shaped region extending in the circumferential direction R1. The sliding region 112 of part 2 is slidable relative to part 1 via the lubricating fluid 12.

[0026] Furthermore, the surface 8 of part 2 has an intermediate region 142, an uneven structure region 122, and a smooth surface region 132. Each of the intermediate region 142, the uneven structure region 122, and the smooth surface region 132 is a band-shaped region extending in the circumferential direction R1.

[0027] In the gap 3, the intermediate region 142, the uneven structure region 122, and the smooth surface region 132 are arranged in this order along the inner surface 103 in the direction from the sliding region 112 toward the outside of the unit 100. That is, the uneven structure region 122 is located along the inner surface 103 between the sliding region 112 and the smooth surface region 132. The intermediate region 142 is located along the inner surface 103 between the sliding region 112 and the uneven structure region 122.

[0028] The outer surface 101 (surface 5) of part 1 faces the sliding region 112, intermediate region 142, uneven structure region 122, and smooth surface region 132 of part 2. That is, the sliding region 112, intermediate region 142, uneven structure region 122, and smooth surface region 132 of part 2 overlap the outer surface 101 (surface 5) of part 1 in a direction perpendicular to the rotation axis C1. Also, the inner region 162 of part 2 is exposed on the inside of unit 100. Therefore, the inner region 162 of part 2 does not face the outer surface 101 of part 1.

[0029] Furthermore, surface 5 of part 1 has an intermediate region 143, an uneven structure region 123, and a smooth surface region 133. Each of the intermediate region 143, the uneven structure region 123, and the smooth surface region 133 is a band-shaped region extending in the circumferential direction R1.

[0030] In the gap 3, the intermediate region 143, the uneven structure region 123, and the smooth surface region 133 are arranged in this order along the outer surface 101 in the direction toward the inside of the unit 100 from the sliding region 111. That is, the uneven structure region 123 is located along the outer surface 101 between the sliding region 111 and the smooth surface region 133. The intermediate region 143 is located along the outer surface 101 between the sliding region 111 and the uneven structure region 123.

[0031] The inner surface 103 (surface 8) of part 2 faces the intermediate region 143, the uneven structure region 123, and the smooth surface region 133 of part 1. That is, the intermediate region 143, the uneven structure region 123, and the smooth surface region 133 of part 1 overlap the inner surface 103 (surface 8) of part 2 in a direction perpendicular to the rotation axis C1.

[0032] Furthermore, the surface 8 of part 2 has an intermediate region 144, an uneven structure region 124, and a smooth surface region 134. Each of the intermediate region 144, the uneven structure region 124, and the smooth surface region 134 is a band-shaped region extending in the circumferential direction R1.

[0033] In the gap 3, the intermediate region 144, the uneven structure region 124, and the smooth surface region 134 are arranged in this order along the inner surface 103 in the direction from the sliding region 112 toward the inside of the unit 100. That is, the uneven structure region 124 is located along the inner surface 103 between the sliding region 112 and the smooth surface region 134. The intermediate region 144 is located along the inner surface 103 between the sliding region 112 and the uneven structure region 124.

[0034] The outer surface 101 (surface 5) of part 1 faces the intermediate region 144, the uneven structure region 124, and the smooth surface region 134 of part 2. That is, the intermediate region 144, the uneven structure region 124, and the smooth surface region 134 of part 2 overlap the outer surface 101 (surface 5) of part 1 in a direction perpendicular to the rotation axis C1.

[0035] As described above, surface 5 has a region group 110 including an intermediate region 141, an uneven structure region 121, and a smooth surface region 131, and a region group 130 including an intermediate region 143, an uneven structure region 123, and a smooth surface region 133. Also, surface 8 has a region group 120 including an intermediate region 142, an uneven structure region 122, and a smooth surface region 132, and a region group 140 including an intermediate region 144, an uneven structure region 124, and a smooth surface region 134.

[0036] The sliding region 111 and region group 110 will be described below. The sliding region 112 has the same configuration as the sliding region 111, the uneven structure region 122, the uneven structure region 123, and the uneven structure region 124 each have the same configuration as the uneven structure region 121, the smooth surface region 132, the smooth surface region 133, and the smooth surface region 134 each have the same configuration as the smooth surface region 131, and the intermediate region 142, the intermediate region 143, and the intermediate region 144 each have the same configuration as the intermediate region 141. For this reason, the descriptions of the sliding region 112, region group 120, region group 130, and region group 140 will be omitted.

[0037] Figure 3 is an enlarged perspective view showing a portion of the outer surface 101 of part 1 according to the first embodiment. Figure 3 shows a perspective view of the area enclosed by circle B1 shown in Figure 2 on surface 5 of the outer surface 101.

[0038] In the first embodiment, an intermediate region 141 is located adjacent to the sliding region 111, an uneven structure region 121 is located adjacent to the intermediate region 141, and a smooth surface region 131 is located adjacent to the uneven structure region 121. Lubricating fluid 12 is provided in the sliding region 111, the intermediate region 141, and the uneven structure region 121.

[0039] The surface 5 of part 1 has at least one projection 170 extending in the circumferential direction R1. The sliding region 111 is provided on the projection 170. The distance between the sliding region 111 and part 2 is smaller than the distance between the uneven structure region 121 and part 2. By reducing the distance between the sliding region 111 and part 2, rattle due to sliding can be suppressed, and highly accurate relative movement can be achieved. By providing the projection 170, the distance between the sliding region 111 and part 2 can be reduced while avoiding contact between the uneven structure region 121 and part 2.

[0040] The uneven structure region 121 has an uneven structure 180 which includes a base surface 14 and a plurality of protrusions 181 that protrude from the base surface 14. The protrusions 170 protrude from the intermediate region 141 and from the base surface 14 of the uneven structure region 121.

[0041] The sliding region 111, the intermediate region 141, and the smooth surface region 131 are, for example, mirror-like surfaces, while the uneven structure region 121 is, for example, a rough surface. Hereinafter, the arithmetic mean roughness Ra of the sliding region 111 at a reference length of 700 μm will be denoted as arithmetic mean roughness Ra1, the arithmetic mean roughness Ra of the uneven structure region 121 at a reference length of 700 μm will be denoted as arithmetic mean roughness Ra2, the arithmetic mean roughness Ra of the smooth surface region 131 at a reference length of 700 μm will be denoted as arithmetic mean roughness Ra3, and the arithmetic mean roughness Ra of the intermediate region 141 at a reference length of 700 μm will be denoted as arithmetic mean roughness Ra4.

[0042] In the first embodiment, the arithmetic mean roughness Ra1 of the sliding region 111, the arithmetic mean roughness Ra4 of the intermediate region 141, and the arithmetic mean roughness Ra3 of the smooth surface region 131 are smaller than the arithmetic mean roughness Ra2 of the uneven structure region 121. In other words, the arithmetic mean roughness Ra2 of the uneven structure region 121 is larger than the arithmetic mean roughness Ra1 of the sliding region 111, the arithmetic mean roughness Ra4 of the intermediate region 141, and the arithmetic mean roughness Ra3 of the smooth surface region 131.

[0043] In summary, regarding the relative magnitudes of the arithmetic mean roughness Ra1 to Ra4, (Ra1, Ra4 or Ra3) < (Ra2). Note that in the first embodiment, the relative magnitudes of the arithmetic mean roughness Ra1, arithmetic mean roughness Ra3, and arithmetic mean roughness Ra4 are not considered.

[0044] Figure 4(a) is an explanatory diagram of the uneven structure 180 according to the first embodiment. Figures 4(b) to 4(f) are explanatory diagrams of the uneven structure 180 according to a modified example of the first embodiment. As shown in Figure 4(a), the uneven structure 180 has a plurality of protrusions 181. Each of the plurality of protrusions 181 protrudes from the base surface 14 and is spaced apart from one another. Each of the plurality of protrusions 181 shown in Figure 4(a) is frustoconical in shape. However, the shape of each of the plurality of protrusions 181 is not limited to a frustoconical shape, and any shape such as a cone shape as shown in Figure 4(b) or a cylindrical shape as shown in Figure 4(c) may be used as long as it has the function of sealing the lubricating fluid 12. Furthermore, although the case in which the uneven structure 180 has a plurality of protrusions 181 projecting from the base surface 14 has been described, it is not limited to this, and the uneven structure 180 may have a plurality of recesses 182 that are recessed from the base surface 14, as shown in Figures 4(d), 4(e), or 4(f), instead of, or in addition to, the plurality of protrusions 181. The shape of each of the plurality of recesses 182 may also be any shape, such as a frustoconical shape as shown in Figure 4(d), a conical shape as shown in Figure 4(e), or a cylindrical shape as shown in Figure 4(f).

[0045] Next, the effect of suppressing the seepage of the lubricating fluid 12 will be explained. Figures 5(a) and 5(b) are explanatory diagrams of a part of the uneven structure region 121 and a part of the smooth surface region 131 according to the first embodiment. Using Figures 5(a) and 5(b), the distance D1 between two adjacent protrusions 181 of the multiple protrusions 181 of the uneven structure region 121 will be explained. Note that if the uneven structure 180 has multiple recesses 182 as shown in Figures 4(d) to 4(f), the distance D1 is the distance between two adjacent recesses 182 of the multiple recesses 182.

[0046] Figures 5(a) and 5(b) show a portion of the arrangement of the protrusions 181 of the uneven structure 180, viewed in the direction normal to the base surface 14 of the uneven structure region 121. In Figures 5(a) and 5(b), there is an unshown sliding region 111 to the left of the uneven structure region 121, and in Figures 5(a) and 5(b), the right side of the smooth surface region 131 is the outside of the unit 100. Multiple protrusions 181 are arranged on the base surface 14 at a distance D1.

[0047] As shown in Figure 5(b), a capillary force F1 acts on the lubricating fluid 12, causing it to try to enter between two adjacent protrusions 181 due to capillary action. This capillary force F1 allows the lubricating fluid 12 to be retained in the uneven structure region 121. Furthermore, in Figure 5(b), a smooth surface region 131 is positioned adjacent to the uneven structure region 121 on the right side, i.e., on the side facing outward from the unit 100 relative to the uneven structure region 121. This reduces the tensile force F2 that pulls the lubricating fluid 12 outward. As a result, it becomes more difficult for the lubricating fluid 12 to move into the smooth surface region 131, and leakage of the lubricating fluid 12 outside the unit 100 can be suppressed. To properly exhibit the interaction between the capillary force F1 and the tensile force F2, it is preferable that the distance between the uneven structure region 122 and the smooth surface region 132 be small. The distance between the uneven structure region 122 and the smooth surface region 132 is, for example, 5 mm or less, preferably 1 mm or less, more preferably 500 μm or less, also preferably 100 μm or less, and may be less than or equal to the distance D1. The arithmetic roughness of the region between the uneven structure region 122 and the smooth surface region 132 may be less than the arithmetic mean roughness Ra2 of the uneven structure region 121, less than the arithmetic mean roughness Ra3 of the smooth surface region 131, and may be about the same as the arithmetic mean roughness Ra4 of the intermediate region 141.

[0048] Furthermore, even when the uneven structure 180 has multiple recesses 182, similar to the multiple protrusions 181, the lubricating liquid 12 can be retained in the uneven structure region 121 by capillary force due to capillary action. In addition, it becomes more difficult for the lubricating liquid 12 to advance into the smooth surface region 131, thereby suppressing the lubricating liquid 12 from seeping outside the unit 100. In other words, the uneven structure region 121 and the smooth surface region 131 can seal the lubricating liquid 12 in the gap 3.

[0049] Next, the arrangement of the multiple protrusions 181 will be described in detail. Figure 6(a) is an explanatory diagram of a part of the uneven structure region 121 and a part of the smooth surface region 131 according to the first embodiment. As shown in Figure 6(a), the multiple protrusions 181 are arranged in a honeycomb pattern. Figure 6(b) is an explanatory diagram of a part of the uneven structure region 121 and a part of the smooth surface region 131 according to a modified example of the first embodiment. As shown in Figure 6(b), the multiple protrusions 181 may be arranged in a grid pattern.

[0050] The multiple protrusions 181 are arranged in at least one row. Of the multiple protrusions 181, the protrusions 181 constituting one row are arranged in a direction intersecting the direction from the uneven structure region 121 toward the smooth surface region 131. If the multiple protrusions 181 are arranged in multiple rows, the multiple rows are spaced apart from each other in the direction from the uneven structure region 121 toward the smooth surface region 131.

[0051] Furthermore, the arrangement pattern of the multiple protrusions 181 may be any arrangement other than a grid arrangement or honeycomb arrangement, as long as the distance D1 is such that the lubricating fluid 12 can be effectively held by capillary action. For example, a random arrangement may be used. Also, in the case where the uneven structure 180 has multiple recesses 182, various arrangement patterns are possible, similar to the arrangement pattern of the multiple protrusions 181.

[0052] Next, the relationship between distance D1 and the sealing performance of the lubricating fluid 12 will be explained. Figure 7 is a diagram showing the results of the sealing performance of the lubricating fluid 12 when the distance D1 between the two protrusions 181 according to the first embodiment is changed. Specifically, Figure 7 shows the results of the sealing performance of the lubricating fluid 12 when the distance D1 is changed, in the configuration shown in Figure 4(a), where the height H of each of the multiple protrusions 181 is 20 μm and the width D2, which is the diameter of each of the multiple protrusions 181, is 50 μm. The letters A, B, and C shown in the sealing results of the lubricating fluid in Figure 7 indicate ranks, where rank A indicates no leakage of the lubricating fluid 12, rank B indicates that a small amount of the lubricating fluid 12 leaked out from the gap 3, and rank C indicates that most of the lubricating fluid 12 leaked out from the gap 3.

[0053] When the distance D1 was 40 μm or less, the sealing performance of the lubricant 12 was very high. When the distance D1 was greater than 40 μm but 80 μm or less, a small amount of the lubricant 12 seeped out from the gap 3, but there was still a sealing effect.

[0054] When the distance D1 was between 90 and 110 μm, the lubricating fluid 12 could not be sufficiently sealed in the gap 3. Thus, the result showed that the sealing performance of the lubricating fluid 12 was higher as the distance D1 decreased. This is thought to be because, as mentioned above, the capillary force F1 is higher as the distance D1 decreases.

[0055] In summary, the distance D1 between two adjacent protrusions 181 is preferably 80 μm or less, and more preferably 40 μm or less. Furthermore, the distance D1 between two adjacent protrusions 181 is preferably 2 μm or more. Similarly, when the uneven structure 180 has a plurality of recesses 182, the distance D1 between two adjacent recesses 182 is preferably 80 μm or less, and more preferably 40 μm or less. Furthermore, the distance D1 between two adjacent recesses 182 is preferably 2 μm or more.

[0056] Next, the height H of each of the multiple protrusions 181 of the uneven structure region 121 will be explained using Figures 8(a) and 8(b). Figures 8(a) and 8(b) are cross-sectional views of a part of the uneven structure region 121 according to the first embodiment. The height H of each of the multiple protrusions 181 is the height relative to the base surface 14.

[0057] As shown in Figure 8(a), when the height H of each protrusion 181 is sufficiently large, the capillary force F1 can be sufficiently large, and the lubricating liquid 12 is retained between the multiple protrusions 181. On the other hand, as shown in Figure 8(b), when the height H of each of the multiple protrusions 181 is small, the lubricating liquid 12 cannot be retained between the multiple protrusions 181, and it is difficult to retain the lubricating liquid 12 by the capillary force F1.

[0058] Therefore, the height H of each of the multiple protrusions 181 for holding the lubricating liquid 12 by capillary force F1 is preferably 1 μm or more, and more preferably 10 μm or more. The upper limit of the height H is preferably less than half the width of the gap between the opposing part 2. Furthermore, the height H of each of the multiple protrusions 181 is preferably 100 μm or less, and more preferably 50 μm or less.

[0059] The above describes the case where the uneven structure 180 has a plurality of protrusions 181. However, when the uneven structure 180 has a plurality of recesses 182, it is preferable that the depth H of each of the recesses 182 is the depth relative to the base surface 14 and is within the same range as the height H of each of the protrusions 181.

[0060] Next, the arithmetic mean roughness Ra2 of the uneven structure region 121 will be described. The arithmetic mean roughness Ra2 of the uneven structure region 121 is determined by the height H and distance D1 of each of the multiple protrusions 181. As described above, from the relationship between the height H and distance D1 of each of the multiple protrusions 181, it is preferable that the height H of each protrusion 181 is large and the distance D1 is small. This means that it is preferable for the arithmetic mean roughness Ra2 of the uneven structure 180 to be as large as possible. Specifically, it is preferable that the arithmetic mean roughness Ra2 of the uneven structure region 121 exceeds 0.5 μm. Furthermore, it is more preferable that the arithmetic mean roughness Ra2 of the uneven structure region 121 be 1.6 μm or more, even more preferable that it be 3.2 μm or more, and even more preferable that it be 5.0 μm or more.

[0061] Furthermore, within the range of the arithmetic mean roughness Ra2 of the uneven structure region 121, it is particularly preferable that it be between 1.6 μm and 100 μm, and more preferably between 3.2 μm and 10 μm.

[0062] Furthermore, in order to avoid contact between the uneven structure region 121 and the opposing component 2, the arithmetic mean roughness Ra2 of the uneven structure region 121 is preferably 100 μm or less, and more preferably 10 μm or less.

[0063] Next, the width D2 of each of the multiple protrusions 181 of the uneven structure 180 will be described. As mentioned above, the capillary force F1 acts between the multiple protrusions 181 of the uneven structure 180, allowing the lubricating fluid 12 to be held by the multiple protrusions 181. If the width D2 of the protrusions 181 is too large, the capillary force F1 will be insufficient, so it is preferable that the width D2 of the protrusions 181 be as small as possible. Specifically, the width D2 of each of the multiple protrusions 181 is preferably 100 μm or less, and more preferably 50 μm or less. If the uneven structure 180 has multiple recesses 182, the width D2 of each of the multiple recesses 182 is preferably 100 μm or less, and more preferably 50 μm or less.

[0064] Next, the arithmetic mean roughness Ra3 of the smooth surface region 131 will be described. Figure 9 shows the results of the sealing performance of the lubricating fluid 12 when the arithmetic mean roughness Ra3 of the smooth surface region 131 of the first embodiment is changed. Specifically, Figure 9 shows the results of the sealing performance of the lubricating fluid 12 when the surface roughness Ra3 of the smooth surface region 131 is changed, in the configuration shown in Figure 4(a), where the height H of each of the multiple protrusions 181 is 20 μm, the width D2 which is the diameter of each of the multiple protrusions 181 is 50 μm, and the distance D1 is 10 μm. The letters A, B, and C shown in the sealing results of the lubricating fluid in Figure 9 indicate ranks, rank A indicates that there is no leakage of the lubricating fluid 12, rank B indicates that a small amount of the lubricating fluid 12 leaked out from the gap 3, and rank C indicates that most of the lubricating fluid 12 leaked out from the gap 3.

[0065] When the arithmetic mean roughness Ra3 of the smooth surface region 131 was 0.5 μm or less, the sealing performance of the lubricant 12 was very high. When the arithmetic mean roughness Ra3 of the smooth surface region 131 was 0.55 μm, a small amount of the lubricant 12 seeped out from the gap 3, but there was still a sealing effect. Furthermore, considering the machinability for machining the smooth surface region 131 to a mirror finish, it is preferable that the arithmetic mean roughness Ra3 of the smooth surface region 131 be 0.01 μm or more.

[0066] When the arithmetic mean roughness Ra3 of the smooth surface region 131 was between 0.66 and 0.81 μm, the lubricating liquid 12 could not be adequately sealed in the gap 3. This is because, as mentioned above, the smaller the arithmetic mean roughness Ra3 of the smooth surface region 131, the smaller the tensile force F2 that pulls the lubricating liquid 12 toward the smooth surface region 131.

[0067] In summary, it is preferable that the arithmetic mean roughness Ra3 of the smooth surface region 131 is 0.01 μm or more and 0.55 μm or less. More preferably, the arithmetic mean roughness Ra3 of the smooth surface region 131 is 0.5 μm or less. More preferably, the arithmetic mean roughness Ra3 of the smooth surface region 131 is 0.24 μm or more.

[0068] Furthermore, in the first embodiment, the sliding region 111 is preferably mirror-finished, similar to the smooth surface region 131. That is, the arithmetic mean roughness Ra1 of the sliding region 111 is preferably 0.01 μm or more and 0.55 μm or less. More preferably, the arithmetic mean roughness Ra1 of the sliding region 111 is 0.5 μm or less. More preferably, the arithmetic mean roughness Ra1 of the sliding region 111 is 0.24 μm or more.

[0069] Next, the surface tension of the liquid and the sealing properties of the liquid will be explained. Figures 10(a) and 10(b) are cross-sectional views of a part of the uneven structure region 121 of the first embodiment. As shown in Figure 10(a), by placing water 16 in the uneven structure region 121, the uneven structure region 121 and the air layer 17 support the water 16, and by increasing the apparent contact angle θ generated by the surface tension of the water 16, a good water-repellent state is achieved. Generally, the surface tension of water is 72 mN / m, and the lubricating liquid 12 of the first embodiment is, for example, 10 to 30 mN / m. Surface tension is the force that causes a liquid to stick together.

[0070] On the other hand, in the first embodiment, as shown in Figure 10(b), the lubricating liquid 12 is placed in the uneven structure region 121. As a result, the surface tension of the lubricating liquid 12 is low, and the lubricating liquid 12 is held between the multiple protrusions 181 of the uneven structure region 121, which generates a capillary force F1 and provides sealing properties to the lubricating liquid 12.

[0071] As described above, according to the first embodiment, since the surface 5 on the outer surface 101 of part 1 that faces part 2 has an uneven structure region 121 and a smooth surface region 131, it is possible to suppress the seepage of lubricating fluid 12 from between part 1 and part 2 to the outside of unit 100. This makes it possible to prevent lubricating fluid 12 from adhering to the user or member when, for example, the user or member touches the outer surface of unit 100.

[0072] Furthermore, according to the first embodiment, the surface 8 on the inner surface 103 of part 2 that faces part 1 has an uneven structure region 122 and a smooth surface region 132 with the same configuration as the uneven structure region 121 and smooth surface region 131 of the surface 5 of part 1, so that the seepage of lubricating fluid 12 from between part 1 and part 2 to the outside of unit 100 can be effectively suppressed.

[0073] Furthermore, according to the first embodiment, since the surface 5 of part 1 has an uneven structure region 123 and a smooth surface region 133 with the same configuration as the uneven structure region 121 and the smooth surface region 131, it is possible to suppress the seepage of lubricating fluid 12 from between part 1 and part 2 into the inside of unit 100. This makes it possible to suppress the decrease in lubricating fluid 12 and the resulting decrease in sliding performance in the sliding region 111 (112).

[0074] Furthermore, according to the first embodiment, since the surface 8 of part 2 has an uneven structure region 124 and a smooth surface region 134 with the same configuration as the uneven structure region 121 and the smooth surface region 131, it is possible to suppress the seepage of lubricating fluid 12 from between part 1 and part 2 into the inside of unit 100. This makes it possible to suppress the decrease in lubricating fluid 12 and the resulting decrease in sliding performance in the sliding region 111 (112).

[0075] In other words, by having either region group 130 or region group 140 in unit 100, it is possible to suppress the decrease in lubricant 12 and the resulting reduction in sliding performance in the sliding region 111 (112). Furthermore, by having both region group 130 and region group 140 in unit 100, it is possible to effectively suppress the decrease in lubricant 12 and the resulting reduction in sliding performance in the sliding region 111 (112).

[0076] With the above configuration, in the first embodiment, it is possible to suppress the lubricating fluid 12 from seeping out of the gap 3 between part 1 and part 2.

[0077] In the first embodiment, the case described was that surface 5 of part 1 has region group 110 and region group 130, and surface 8 of part 2 has region group 120 and region group 140, but the invention is not limited to this. That is, from the viewpoint of suppressing the seepage of lubricating fluid 12 to the outside of unit 100, region group 110, region group 120, region group 130, and region group 140 may be omitted, except for region group 110 or region group 120. For example, if region group 110 is omitted, part 2 having region group 120 becomes the first part, and part 1 becomes the second part. Then, the sliding region 112 of part 2 becomes the first region, the uneven structure region 122 becomes the second region, and the smooth surface region 132 becomes the third region.

[0078] Furthermore, in the first embodiment, the case in which region group 110 has an intermediate region 141, that is, the case in which surface 5 of part 1 has an intermediate region 141, was described, but it is not limited to this, and the intermediate region 141 may be omitted in surface 5. Similarly, the intermediate region 142 may be omitted in region group 120, the intermediate region 143 may be omitted in region group 130, or the intermediate region 144 may be omitted in region group 140.

[0079] <Second Embodiment> A second embodiment will now be described. Hereinafter, elements denoted by the same reference numerals as those in the above-described embodiment will have substantially the same configuration and function as those described in the above-described embodiment unless otherwise specified. The differences from the above-described embodiment will be the main focus of this description.

[0080] Figure 11 is an enlarged perspective view showing a portion of the outer surface 101 of part 1 according to the second embodiment. Figure 11 shows a perspective view of the area enclosed by circle B1 shown in Figure 2 on surface 5 of the outer surface 101.

[0081] In the second embodiment, the arithmetic mean roughness Ra4 of the intermediate region 141 differs from that of the first embodiment. The arithmetic mean roughness Ra4 of the intermediate region 141 is smaller than the arithmetic mean roughness Ra2 of the uneven structure region 121 and larger than the arithmetic mean roughness Ra1 of the sliding region 111. The arithmetic mean roughness Ra4 of the intermediate region 141 is a value between the arithmetic mean roughness Ra3 of the smooth surface region 131 and the arithmetic mean roughness Ra2 of the uneven structure region 121. That is, the arithmetic mean roughness Ra4 of the intermediate region 141 is smaller than the arithmetic mean roughness Ra2 of the uneven structure region 121 and larger than the arithmetic mean roughness Ra3 of the smooth surface region 131.

[0082] Furthermore, the arithmetic mean roughness Ra3 of the smooth surface region 131 is smaller than the arithmetic mean roughness Ra2 of the uneven structure region 121. Also, the arithmetic mean roughness Ra1 of the sliding region 111 is smaller than the arithmetic mean roughness Ra2 of the uneven structure region 121. In addition, the arithmetic mean roughness Ra1 of the sliding region 111 is smaller than the arithmetic mean roughness Ra4 of the intermediate region 141.

[0083] In summary, the relationship between the arithmetic mean roughness values ​​Ra1 to Ra4 is (Ra1 or Ra3) < (Ra4) < (Ra2). Note that in the second embodiment, the relationship between the calculated mean roughness value Ra1 and the arithmetic mean roughness value Ra3 is not considered.

[0084] As described above, because the intermediate region 141 has an intermediate roughness, as the lubricant 12 spreads from the sliding region 111 to the intermediate region 141, the lubricant 12 diffuses in the circumferential direction R1 perpendicular to the direction toward the outside of the unit 100. Furthermore, the lubricant 12 can be retained in the intermediate region 141 as well. Due to these two points, the tensile force F2 that causes the lubricant 12 to seep out at the boundary between the uneven structure region 121 and the smooth surface region 131 can be reduced, and the seepage of lubricant 12 from between part 1 and part 2 toward the outside of the unit 100 can be effectively suppressed.

[0085] Furthermore, from the viewpoint of suppressing the seepage of the lubricating fluid 12, the arithmetic mean roughness Ra4 of the intermediate region 141 is preferably 0.5 μm or more and 1.6 μm or less. The preferred numerical ranges for the arithmetic mean roughness Ra1 of the sliding region 111, the arithmetic mean roughness Ra2 of the uneven structure region 121, and the arithmetic mean roughness Ra3 of the smooth surface region 131 are as described in the first embodiment.

[0086] Furthermore, according to the second embodiment, the surface 8 on the inner surface 103 of part 2 that faces part 1 has an intermediate region 142 with a configuration similar to the intermediate region 141 of the surface 5 of part 1, so that the seepage of lubricating fluid 12 from between part 1 and part 2 to the outside of unit 100 can be effectively suppressed.

[0087] Furthermore, according to the second embodiment, since the surface 5 of part 1 has an intermediate region 143 with the same configuration as the intermediate region 141, it is possible to effectively suppress the seepage of lubricating fluid 12 from between part 1 and part 2 into the inside of unit 100. This makes it possible to suppress the decrease in lubricating fluid 12 and the resulting decrease in sliding performance in the sliding region 111 (112).

[0088] Furthermore, according to the second embodiment, since the surface 8 of part 2 has an intermediate region 144 with the same configuration as the intermediate region 141, it is possible to effectively suppress the seepage of lubricating fluid 12 from between part 1 and part 2 into the inside of unit 100. This makes it possible to suppress the decrease in lubricating fluid 12 and the resulting decrease in sliding performance in the sliding region 111 (112).

[0089] In other words, by having either region group 130 or region group 140 in unit 100, it is possible to suppress the decrease in lubricant 12 and the resulting reduction in sliding performance in the sliding region 111 (112). Furthermore, by having both region group 130 and region group 140 in unit 100, it is possible to effectively suppress the decrease in lubricant 12 and the resulting reduction in sliding performance in the sliding region 111 (112).

[0090] With the above configuration, in the second embodiment, it is possible to effectively suppress the lubricating fluid 12 from seeping out of the gap 3 between part 1 and part 2.

[0091] In the second embodiment, the case described was that surface 5 of part 1 has region group 110 and region group 130, and surface 8 of part 2 has region group 120 and region group 140, but the embodiment is not limited to this. That is, from the viewpoint of suppressing the seepage of lubricating fluid 12 to the outside of unit 100, region group 110, region group 120, region group 130, and region group 140 may be omitted, except for region group 110 or region group 120. For example, if region group 110 is omitted, part 2 having region group 120 becomes the first part, and part 1 becomes the second part. Then, the sliding region 112 of part 2 becomes the first region, the uneven structure region 122 becomes the second region, and the smooth surface region 132 becomes the third region.

[0092] <Third Embodiment> A third embodiment will now be described. In the following description, elements denoted by the same reference numerals as those in the above embodiments will have substantially the same configuration and function as those described in the above embodiments unless otherwise specified, and the differences from the above embodiments will be described primarily.

[0093] Figure 12 is an enlarged perspective view showing a portion of the outer surface 101Y of the part relating to the comparative example. Figure 12 shows a perspective view of the area on the outer surface 101Y corresponding to the area enclosed by circle B1 shown in Figure 2. The outer surface 101Y of Comparative Example 2 does not have areas of uneven structure or smooth surface.

[0094] As shown in Figure 12, the outer surface 101Y has ridge-like protrusions 190Y extending from the sliding region 111Y toward the outside of the unit. The protrusions 190Y are, for example, burrs resulting from the mold's cut lines in injection molding. If the protrusions 190Y are present, there is a risk that the lubricating fluid 12 may seep out of the unit along the protrusions 190Y.

[0095] Figure 13(a) is an enlarged perspective view of a part of the outer surface 101 of part 1 according to the third embodiment. Figure 13(b) is an enlarged plan view of a part of the outer surface 101 of part 1 according to the third embodiment. Figure 13(a) shows a perspective view of the area on the outer surface 101 corresponding to the area enclosed by circle B1 shown in Figure 2, and Figure 13(b) shows a plan view of the area on the outer surface 101 corresponding to the area enclosed by circle B1 shown in Figure 2.

[0096] The surface 5 of the outer surface 101 has a sliding region 111, an uneven structure region 121, and a smooth surface region 131, similar to the first embodiment. The outer surface 101 also has ridge-like projections 190 that extend from the sliding region 111 toward the outside of the unit 100. The projections 190 are, for example, burrs caused by the mold cleavage lines in injection molding. The projections 190 are ridge-like projections that extend in the direction of the rotation axis C1 (Figure 1(a)).

[0097] The protrusion 190 is formed in at least the uneven structure region 121 and the smooth surface region 131. That is, the uneven structure region 121 and the smooth surface region 131 are located on both sides of the protrusion 190 in the circumferential direction R1. This prevents the lubricating fluid 12 from seeping out of the unit 100 along the protrusion 190 by the uneven structure region 121 and the smooth surface region 131.

[0098] Although not shown in Figures 13(a) and 13(b), it is preferable that an intermediate region 141 (Figure 11), as described in the second embodiment, is positioned between the sliding region 111 and the uneven structure region 121. This allows the intermediate region 141, the uneven structure region 121, and the smooth surface region 131 to effectively suppress the lubricating fluid 12 from seeping out of the unit 100 along the protrusions 190.

[0099] Next, we will describe a manufacturing method for producing parts 1 and 2 of unit 100. The following describes a manufacturing method for producing parts 1 and 2 by injection molding using a mold.

[0100] Figures 14(a) to 14(e) schematically show the injection molding process for manufacturing a resin molded product 280 according to the third embodiment. The resin molded product 280 is either part 1 or part 2. The resin molded product 280 is manufactured using an injection molding machine 30. As shown in Figure 14(a), the injection molding machine 30 has a cylindrical cylinder 26 and a hopper 27.

[0101] The hopper 27 loads the resin material into the cylinder 26. Thermoplastic materials such as polystyrene, polycarbonate, and polypropylene can be used as the resin material. Alternatively, the resin material may be pre-colored by mixing in pigments or other colorants.

[0102] Cylinder 26 injects molten resin into the cavity, which is the space defined by molds 31 and 32. Inside cylinder 26 is a screw (not shown), which is rotated by a motor (not shown) to send the resin material fed from hopper 27 to the tip of cylinder 26. Cylinder 26 is also equipped with a heater (not shown), and as the resin material fed from hopper 27 is sent through the inside of the cylinder to the tip, it is heated above the glass transition temperature of the resin material and melted into a liquid state. This melted material is then stored in the space at the tip of cylinder 26.

[0103] Figure 14(b) shows the mold clamping process. In the mold clamping process, molds 31 and 32 are clamped together by a mechanism not shown. Molds 31 and 32 are also heated by a heater not shown. The heating temperature of molds 31 and 32 in this process is called the mold temperature.

[0104] Figure 14(c) shows the injection process. In the injection process, the cylinder 26 is pressed against the injection hole portion provided in the mold 32. Furthermore, a hydraulic cylinder (not shown) operates and pushes a screw (not shown) toward the tip of the cylinder 26, injecting the molten resin 28 into the cavities inside the molds 31 and 32. The temperature of the molten resin 28 in this injection process is called the resin temperature.

[0105] Figure 14(d) shows the holding pressure process and the cooling process. In the holding pressure process, the pressure inside the cylinder 26 is controlled to maintain the pressure of the molten resin 28 in the cavity defined by the molds 31 and 32 at a predetermined pressure. This pressure is called the holding pressure. The holding pressure is selected to ensure that the resin 28 reaches every corner of the cavity defined by the molds 31 and 32. In the cooling process following the holding pressure process, the molds 31 and 32 are cooled by a cooling mechanism (not shown). This cools the resin 28 inside the molds 31 and 32 to a temperature below the glass transition temperature, forming the resin molded product 280. The cooling mechanism is configured, for example, to circulate cooling water around the molds 31 and 32.

[0106] Figure 14(e) shows the mold opening and demolding processes. Molds 31 and 32 are opened by a mechanism (not shown). Subsequently, the resin molded product 280 is removed from molds 31 and 32 by a demolding mechanism (not shown). At the stage when molds 31 and 32 are opened, the resin molded product 280 is stuck to the surface of mold 32. The demolding mechanism uses a rod called an ejector pin, which penetrates mold 32, to push the resin molded product 280 stuck to the surface of mold 32 out of mold 32. Through these processes, the resin molded product 280 is obtained.

[0107] Figure 15(a) is a photograph of a portion of the uneven structure on the surface of the mold 31 according to the third embodiment, observed with an electron microscope. Figure 15(b) is a photograph of the uneven structure region 121 of the part 1 according to the third embodiment, observed with an electron microscope. In Figure 15(b), it can be confirmed that the honeycomb arrangement of fine shapes, onto which the mold shape of Figure 15(a) has been transferred, is formed on the uneven structure region 121 of the part 1. By aligning the convex direction of the multiple protrusions 181 and / or the concave direction of the multiple recesses 182 of the uneven structure region 121 with the mold opening direction of the mold 31 and the mold 32, the uneven structure region of the mold 31 can be transferred to the uneven structure region 121 of the part 1, and the release properties of the part 1 from the mold 31 are also improved. In this example, the mold 31 having the uneven structure is a movable mold, and the mold 32 is a fixed mold. In this way, gate marks can be placed on the inner surface 102 of the part 1, and gate marks can be prevented from being generated on the outer surface 101. However, the mold 31 having an uneven structure may be made fixed, and the mold 32 may be made movable.

[0108] Next, a method for manufacturing the mold 31 will be described. Possible methods for manufacturing the mold 31 include a method for manufacturing a molded product with an uneven structure and smooth surfaces by transferring depressions and smooth surfaces formed by cutting to a resin, and a method for manufacturing a molded product with an uneven structure by transferring depressions and smooth surfaces formed by laser processing to a resin. In the third embodiment, depressions and smooth surfaces are formed on the surface of the mold 31 by laser processing.

[0109] Figure 16(a) is a schematic perspective view showing an example of the configuration of a laser processing machine 21 according to the third embodiment. The laser processing machine 21 shown in Figure 16(a) is used to form a mold 31 by laser processing a metal base material 20.

[0110] The laser processing machine 21 has a laser head 22. The laser processing machine 21 is configured so that the laser head 22 can move along three axes: linear axis X, linear axis Y, and linear axis Z. The laser head 22 has a galvanometer mirror (not shown) built into it. The laser processing machine 21 may be configured so that the laser head 22 can move in even more directions.

[0111] The laser head 22 is moved by a drive mechanism (not shown) according to the amount of movement of each axis programmed in the NC data 24. Meanwhile, the laser head 22 emits laser light according to the NC data 24 and scans the laser light on the base material 20 using a galvanometer mirror. In this way, the base material 20 can be processed into a predetermined shape by the laser head 22.

[0112] Figure 16(b) is an enlarged view showing the processing performed on the surface of the base material 20 by the laser processing machine 21 according to the third embodiment. Figure 16(b) shows a cross-section of the base material 20 as seen from the cross-sectional direction.

[0113] The mold 31 can take on various shapes, such as flat or complex curved surfaces, corresponding to the shape of the resin molded product 280. Therefore, the base surface 14 viewed from the cross-sectional direction is not necessarily a straight line, but Figure 16(b) shows an example where it is a straight line.

[0114] A laser beam 23 is emitted from the laser head 22 to form multiple processing holes 25 in the base material 20. The laser beam can be infrared light with a wavelength of, for example, 1064 nm and a pulse width of femtoseconds, but other types of laser light may also be used.

[0115] As shown in Figure 16(b), the laser beam is repeatedly moved by the galvanometer mirror by the pitch P of the uneven structure, and the laser beam is irradiated onto the mold 31 to form multiple processing holes 25. For the area corresponding to the smooth surface area 131, a smooth surface shape can be formed on the mold 31 by mechanical polishing or laser processing.

[0116] Through the laser processing described above, multiple processed holes are formed as shown in the photograph in Figure 15(a). In the photograph, it can be seen that the multiple processed holes are arranged in a honeycomb pattern. Through this process, a molding die 31 is obtained.

[0117] <Fourth Embodiment> A fourth embodiment will now be described. Hereinafter, elements denoted by the same reference numerals as those in the above embodiments will have substantially the same configuration and function as those described in the above embodiments unless otherwise specified. The differences from the above embodiments will be the main focus of this description.

[0118] Figure 17 is a schematic perspective view of the imaging device 200 according to the fourth embodiment. The imaging device 200 includes a camera body 210 and a detachable interchangeable lens unit 220 attached to the camera body 210.

[0119] The interchangeable lens unit 220 is an example of an optical instrument. The interchangeable lens unit 220 has a substantially cylindrical lens barrel 230 and a lens 240 housed inside the lens barrel 230. The lens barrel 230 is composed of multiple parts, which are assembled together by methods such as screwing, gluing, or fitting. The lens barrel 230 includes unit 100.

[0120] Figure 18(a) is a perspective view of unit 100, which is part of the lens barrel 230 according to the fourth embodiment. Unit 100 of the lens barrel 230 has part 1 and part 2. Part 1 is an example of a first part, and part 2 is an example of a second part.

[0121] One of the parts, part 1 and part 2, is rotatable in the circumferential direction R1, which is the direction of rotation around the rotation axis C1 of the other. In the fourth embodiment, part 2 is rotationally driven relative to part 1 in the circumferential direction R1 around the rotation axis C1 of the unit 100. In the fourth embodiment, part 1 supports part 2 by a sliding region 111.

[0122] Component 1, like the first embodiment, has an outer surface 101 and an inner surface 102 opposite to the outer surface 101. Component 2, like the first embodiment, has an inner surface and an outer surface 104 opposite to the inner surface. The outer surface 101 of component 1 is an example of a first surface. The inner surface 102 of component 1 is an example of a second surface. The inner surface of component 2 is an example of a third surface. The outer surface 104 of component 2 is an example of a fourth surface.

[0123] Figure 18(b) is a perspective view of part 1 according to the fourth embodiment, and Figure 19 is an enlarged perspective view of part 1 within area D of Figure 18(b). The outer surface 101 of part 1 has a region 151, a sliding region 111, an intermediate region 141, an uneven structure region 121, a smooth surface region 131, and an outer region 161. Each of the regions 151, 111, 141, 121, 131, and 161 is a band-shaped region extending in the circumferential direction R1. The sliding region 111 is an example of a first region, the uneven structure region 121 is an example of a second region, the smooth surface region 131 is an example of a third region, the intermediate region 141 is an example of a fourth region, the region 151 is an example of a fifth region, and the outer region 161 is an example of a sixth region.

[0124] The arrangement of the sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131 is as described in the first embodiment. Along the outer surface 101, the sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131 are arranged between region 151 and outer region 161.

[0125] The inner surface of part 2 faces the region 151, sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131, which are part of the outer surface 101 of part 1. In addition, the outer region 161, which is part of the outer surface 101 of part 1 other than the region 151, sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131, is exposed to the outside of unit 100 without facing the inner surface of part 2.

[0126] Furthermore, the relationship between the arithmetic mean roughness Ra of the sliding region 111, intermediate region 141, uneven structure region 121, and smooth surface region 131 at a reference length of 700 μm is as described in the second embodiment.

[0127] Furthermore, the preferred numerical ranges for the arithmetic mean roughness Ra1 of the sliding region 111, the arithmetic mean roughness Ra2 of the uneven structure region 121, and the arithmetic mean roughness Ra3 of the smooth surface region 131 are as described in the first and second embodiments. Also, the preferred numerical range for the arithmetic mean roughness Ra4 of the intermediate region 141 is as described in the second embodiment.

[0128] With the above configuration, similar to the first or second embodiment, it is possible to suppress the lubricating fluid 12 from seeping out of the gap 3 between part 1 and part 2, i.e., to the outside of unit 100. Specifically, the lubricating fluid 12 tends to seep out in the direction of arrow 250 from the sliding region 111 of part 1 toward the outer region 161. In the fourth embodiment, the intermediate region 141, the uneven structure region 121, and the smooth surface region 131 are arranged in the direction of arrow 250 relative to the sliding region 111. This makes it possible to suppress the lubricating fluid 12 from seeping out of unit 100 of the lens barrel 230, i.e., to the outside of unit 100, i.e., to the outside of lens barrel 230.

[0129] The arithmetic mean roughness Ra of region 151 at a reference length of 700 μm is defined as arithmetic mean roughness Ra5, and the arithmetic mean roughness Ra of outer region 161 at a reference length of 700 μm is defined as arithmetic mean roughness Ra6. In the fourth embodiment, the smooth surface region 131 is mirror-finished, but region 151 and outer region 161 do not need to be mirror-finished. Therefore, it is preferable that the arithmetic mean roughness Ra5 of region 151 and the arithmetic mean roughness Ra6 of outer region 161 are each greater than the arithmetic mean roughness Ra3 of smooth surface region 131. In other words, it is preferable that the arithmetic mean roughness Ra3 of smooth surface region 131 is each smaller than the arithmetic mean roughness Ra5 of region 151 and the arithmetic mean roughness Ra6 of outer region 161.

[0130] Furthermore, since the uneven structure region 121 is roughened, the arithmetic mean roughness Ra5 of region 151 and the arithmetic mean roughness Ra6 of the outer region 161 are both smaller than the arithmetic mean roughness Ra2 of the uneven structure region 121. Note that the outer region 161 may be decoratively processed, in which case the arithmetic mean roughness Ra6 of the outer region 161 may be larger than the arithmetic mean roughness Ra5 of region 151.

[0131] Furthermore, the outer surface 101 of part 1 has ridge-like protrusions 190 arranged over at least the uneven structure region 121 and the smooth surface region 131, similar to the third embodiment. In the fourth embodiment, the protrusions 190 are arranged over region 151, the sliding region 111, the intermediate region 141, the uneven structure region 121, the smooth surface region 131, and the outer region 161. The protrusions 190 are, for example, burrs resulting from the mold cleavage lines in injection molding. With this configuration, the uneven structure region 121 and the smooth surface region 131 can prevent the lubricating fluid 12 from seeping out of the unit 100 via the protrusions 190.

[0132] Furthermore, the intermediate region 141 may be planar as in the second embodiment, but it may also have a stepped portion 18 as shown in Figure 19. Preferably, the height difference of the stepped portion 18 is greater than the height difference of the protruding portion 170. This stepped portion 18 increases the creepage distance between the sliding region 111 and the uneven structure region 121, which is advantageous in suppressing the seepage of the lubricating fluid 12.

[0133] Furthermore, in part 1, a region with the same configuration as the intermediate region 141, the uneven structure region 121, and the smooth surface region 131 may be arranged on the side opposite to the sliding region 111 that faces outward from the unit 100. Also, on the inner surface of part 2, a region with the same configuration as the outer surface 101 of part 1 may be arranged in the region facing part 1.

[0134] <Examples> An embodiment corresponding to the fourth embodiment will be described. Figure 20 is a schematic perspective view of a part of part 1 according to the embodiment. In this embodiment, the distance D1 is 10 μm, the pitch P is 60 μm, the height H is 20 μm, and the width D2 is 50 μm. Each of the multiple protrusions 181 is frustoconical in shape, and the multiple protrusions 181 are arranged in a honeycomb pattern. An intermediate region 141, an uneven structure region 121, and a smooth surface region 131 are provided in the outward direction from the sliding region 111 (direction of arrow 250). Parts 1 and 2 are made of resin molded products made of a resin such as polycarbonate, and the uneven structure region 121, the smooth surface region 131, and the intermediate region 141 of part 1 are formed by injection molding. With this configuration, it is not necessary to install a packing or apply an oil-repellent film, and it is possible to suppress the seepage and spread of lubricating fluid 12 from the sliding region 111 of the lens barrel 230 to the outside of the lens barrel 230.

[0135] [Other variations] This disclosure is not limited to the embodiments described above, and many modifications are possible within the technical concept of this disclosure. Furthermore, the effects described in these embodiments are merely a list of the most preferred effects and are not limited to this disclosure. In addition, two or more of the above-described embodiments and modifications may be combined.

[0136] In the above-described embodiment, the case in which the unit is applied to an interchangeable lens unit was explained, but the unit is not limited to this, and can be applied to optical equipment in which the lens unit is integrated with the camera body.

[0137] Furthermore, while the above unit is preferably applied to optical equipment, it is not limited to optical equipment and can be applied to various devices that include a unit that slides two movable parts together. For example, the above unit can be applied to cameras that have a shutter mechanism, a reflex mechanism that drives a movable mirror, and an image stabilization mechanism that drives a movable image sensor. It can also be applied to office equipment such as printers, copiers, and scanners, medical equipment such as CT and MRI scanners, industrial equipment such as robots and semiconductor manufacturing equipment, and transportation equipment such as vehicles, airplanes, and ships. The relative movement of the two parts is not limited to rotational motion, but may also be linear motion. In addition, one of the two parts may be fixed and the other movable, or both may be movable.

[0138] The disclosures in this specification include not only what is explicitly stated herein, but also all matters that can be inferred from this specification and the drawings attached thereto. Furthermore, the disclosures in this specification include the complement of the individual concepts described herein. That is, if this specification states, for example, "A is B," then even if it omits the statement "A is not B," it can be said that this specification discloses "A is not B." This is because the statement "A is B" presupposes that the case "A is not B" is being considered.

[0139] The above disclosure of embodiments includes the following sections:

[0140] (Section 1) A unit comprising a first part and a second part, wherein one of the first part and the second part is movable relative to the other, and a lubricating fluid is disposed between the first part and the second part, The first surface of the first part has a first region, a second region, and a third region. The first region is slidable to the second component via the lubricating fluid, Along the first surface, the second region is positioned between the first region and the third region. The second region has an uneven structure composed of a plurality of protrusions and / or a plurality of recesses, The distance between two adjacent protrusions and / or the distance between two adjacent recesses is 80 μm or less. The height of each of the multiple protrusions and / or the depth of each of the multiple recesses of the aforementioned uneven structure is 1 μm or more. The width of each of the multiple protrusions and / or the width of each of the multiple recesses of the aforementioned uneven structure is 100 μm or less. The arithmetic mean roughness of the third region at a reference length of 700 μm is between 0.01 μm and 0.55 μm. A unit characterized by the following features.

[0141] (Section 2) The first surface has a fourth region located between the first region and the second region along the first surface, The arithmetic mean roughness of the fourth region at a reference length of 700 μm is less than the arithmetic mean roughness of the second region at a reference length of 700 μm, and greater than the arithmetic mean roughness of the third region. The unit according to item 1, characterized in that it is a unit according to item 1.

[0142] (Section 3) A unit comprising a first part and a second part, wherein one of the first part and the second part is movable relative to the other, and a lubricating fluid is disposed between the first part and the second part, The first surface of the first part has a first region, a second region, a third region, and a fourth region. The first region is slidable to the second component via the lubricating fluid, Along the first surface, the second region is positioned between the first region and the third region, and the fourth region is positioned between the first region and the second region. The second region has an uneven structure composed of a plurality of protrusions and / or a plurality of recesses, The arithmetic mean roughness of the third region at a reference length of 700 μm is smaller than the arithmetic mean roughness of the second region at a reference length of 700 μm. The arithmetic mean roughness of the fourth region at a reference length of 700 μm is less than the arithmetic mean roughness of the second region and greater than the arithmetic mean roughness of the first region. A unit characterized by the following features.

[0143] (Section 4) The arithmetic mean roughness of the fourth region is 0.5 μm or more and 1.6 μm or less. The unit according to item 2 or 3, characterized by the features described herein.

[0144] (Section 5) The arithmetic mean roughness of the third region is 0.5 μm or less. A unit according to any one of items 1 to 4, characterized in that it is a unit according to any one of items 1 to 4.

[0145] (Section 6) The arithmetic mean roughness of the second region is 1.6 μm or more and 100 μm or less. A unit according to any one of claims 1 to 5, characterized in that it is a unit according to any one of claims 1 to 5.

[0146] (Section 7) The arithmetic mean roughness of the second region is 3.2 μm or more and 10 μm or less. A unit according to any one of items 1 to 6, characterized in that it is a unit according to any one of items 1 to 6.

[0147] (Section 8) The distance between two adjacent protrusions and / or the distance between two adjacent recesses is 40 μm or less. A unit according to any one of claims 1 to 7, characterized in that it is a unit according to any one of claims 1 to 7.

[0148] (Section 9) The arithmetic mean roughness of the first region at a reference length of 700 μm is less than the arithmetic mean roughness of the second region. A unit according to any one of claims 1 to 8, characterized in that it is a unit according to any one of claims 1 to 8.

[0149] (Section 10) The first surface has a protrusion, The first region is provided on the protruding portion. A unit according to any one of items 1 to 9, characterized in that it is a unit according to any one of items 1 to 9.

[0150] (Section 11) The first surface has a stepped portion between the first region and the second region. A unit according to any one of claims 1 to 10, characterized in that it is a unit according to any one of claims 1 to 10.

[0151] (Section 12) The first surface has a fifth region and a sixth region, Along the first surface, the first region, the second region, and the third region are arranged between the fifth region and the sixth region. The arithmetic mean roughness of the fifth region at a reference length of 700 μm and the arithmetic mean roughness of the sixth region at a reference length of 700 μm are each greater than the arithmetic mean roughness of the third region. A unit according to any one of items 1 to 11, characterized in that it is a unit according to any one of items 1 to 11.

[0152] (Section 13) The first part has a second surface opposite to the first surface, The second part has a third surface and a fourth surface opposite to the third surface, The third surface faces the first region, the second region, and the third region. A portion of the first surface other than the first, second, and third regions does not face the third surface. A unit according to any one of items 1 to 12, characterized in that it is a unit according to any one of items 1 to 12.

[0153] (Section 14) One of the first and second parts is slidable relative to the other in a rotational direction about its axis. The first surface has striated projections formed in at least the second and third regions and extending in the direction of the axis, A unit according to any one of items 1 to 13, characterized in that it is a unit according to any one of items 1 to 13.

[0154] (Section 15) The plurality of protrusions and / or the plurality of recesses are arranged in a honeycomb pattern. A unit according to any one of items 1 to 14, characterized in that it is a unit according to any one of items 1 to 14.

[0155] (Section 16) The plurality of protrusions and / or the plurality of recesses are cylindrical, conical, or frustoconical in shape. A unit according to any one of claims 1 to 15, characterized in that it is a unit according to any one of claims 1 to 15.

[0156] (Section 17) The first part is a resin molded product. A unit according to any one of items 1 to 16, characterized in that it is a unit according to any one of items 1 to 16.

[0157] (Section 18) The first and second parts are cylindrical in shape. A unit according to any one of claims 1 to 17, characterized in that it is a unit according to any one of claims 1 to 17.

[0158] (Section 19) One of the first and second parts is rotatable relative to the other in a rotational direction about its axis. The unit according to item 18, characterized by the features described herein.

[0159] (Section 20) The telescope tube and The lens housed in the aforementioned lens barrel, and the optical instrument comprising, The lens barrel includes the unit described in any one of items 1 to 19. An optical instrument characterized by the following features. [Explanation of Symbols]

[0160] D1...Distance, D2...Width, 1...Part (First Part), 2...Part (Second Part), 12...Lubricant, 100...Unit, 101...Outer surface (First surface), 102...Inner surface (Second surface), 103...Inner surface (Third surface), 104...Outer surface (Fourth surface), 111...Sliding area (First area), 121...Uneven structure area (Second area), 131...Smooth surface area (Third area), 141...Intermediate area (Fourth area), 151...Area (Fifth area), 161...Outer area (Sixth area), 170...Protrusion, 180...Uneven structure, 181...Convex part, 182...Concave part, 190...Projection, 220...Interchangeable lens unit (Optical instrument), 230...Lens barrel

Claims

1. A unit comprising a first part and a second part, wherein one of the first part and the second part is movable relative to the other, and a lubricating fluid is disposed between the first part and the second part, The first surface of the first component has a first region, a second region, and a third region. The first region is slidable to the second component via the lubricating fluid, Along the first surface, the second region is positioned between the first region and the third region. The second region has an uneven structure composed of a plurality of protrusions and / or a plurality of recesses, The distance between two adjacent protrusions and / or the distance between two adjacent recesses is 80 μm or less. The height of each of the multiple protrusions and / or the depth of each of the multiple recesses of the aforementioned uneven structure is 1 μm or more. The width of each of the multiple protrusions and / or the width of each of the multiple recesses of the aforementioned uneven structure is 100 μm or less. The arithmetic mean roughness of the third region at a reference length of 700 μm is 0.01 μm or more and 0.55 μm or less. A unit characterized by the following features.

2. The first surface has a fourth region positioned between the first region and the second region along the first surface, The arithmetic mean roughness of the fourth region at a reference length of 700 μm is less than the arithmetic mean roughness of the second region at a reference length of 700 μm, and greater than the arithmetic mean roughness of the third region. The unit according to feature 1.

3. A unit comprising a first part and a second part, wherein one of the first part and the second part is movable relative to the other, and a lubricating fluid is disposed between the first part and the second part, The first surface of the first part has a first region, a second region, a third region, and a fourth region. The first region is slidable to the second component via the lubricating fluid, Along the first surface, the second region is positioned between the first region and the third region, and the fourth region is positioned between the first region and the second region. The second region has an uneven structure composed of a plurality of protrusions and / or a plurality of recesses, The arithmetic mean roughness of the third region at a reference length of 700 μm is smaller than the arithmetic mean roughness of the second region at a reference length of 700 μm. The arithmetic mean roughness of the fourth region at a reference length of 700 μm is smaller than the arithmetic mean roughness of the second region and larger than the arithmetic mean roughness of the first region. A unit characterized by the following features.

4. The arithmetic mean roughness of the fourth region is 0.5 μm or more and 1.6 μm or less. The unit according to claim 2 or 3, characterized by the features described herein.

5. The arithmetic mean roughness of the third region is 0.5 μm or less. The unit according to claim 1 or 2.

6. The arithmetic mean roughness of the second region is 1.6 μm or more and 100 μm or less. The unit according to claim 1 or 2.

7. The arithmetic mean roughness of the second region is 3.2 μm or more and 10 μm or less. The unit according to claim 1 or 2.

8. The distance between two adjacent protrusions and / or the distance between two adjacent recesses is 40 μm or less. The unit according to claim 1 or 2.

9. The arithmetic mean roughness of the first region at a reference length of 700 μm is less than the arithmetic mean roughness of the second region. The unit according to claim 1 or 2, characterized by the features described above.

10. The first surface has a protrusion, The first region is provided on the protruding portion, The unit according to any one of claims 1 to 3.

11. The first surface has a stepped portion between the first region and the second region. The unit according to any one of claims 1 to 3.

12. The first surface has a fifth region and a sixth region, Along the first surface, the first region, the second region, and the third region are arranged between the fifth region and the sixth region. The arithmetic mean roughness of the fifth region at a reference length of 700 μm and the arithmetic mean roughness of the sixth region at a reference length of 700 μm are each greater than the arithmetic mean roughness of the third region. The unit according to any one of claims 1 to 3.

13. The first part has a second surface opposite to the first surface, The second part has a third surface and a fourth surface opposite to the third surface, The aforementioned third surface faces the aforementioned first region, the aforementioned second region, and the aforementioned third region. A portion of the first surface other than the first, second, and third regions does not face the third surface. The unit according to any one of claims 1 to 3.

14. One of the first and second parts is slidable relative to the other in a rotational direction about its axis. The first surface has striated projections formed in at least the second and third regions, extending in the direction of the axis. The unit according to any one of claims 1 to 3.

15. The plurality of protrusions and / or the plurality of recesses are arranged in a honeycomb pattern. The unit according to any one of claims 1 to 3.

16. The plurality of protrusions and / or the plurality of recesses are cylindrical, conical, or frustoconical in shape. The unit according to any one of claims 1 to 3.

17. The first part is a resin molded product. The unit according to any one of claims 1 to 3.

18. The first and second parts are cylindrical in shape. The unit according to any one of claims 1 to 3.

19. One of the first and second parts is rotatable relative to the other in a rotational direction about its axis. The unit according to feature 18.

20. The telescope tube and The lens housed in the aforementioned lens barrel, and the optical instrument comprising, The lens barrel includes the unit described in any one of claims 1 to 3. An optical instrument characterized by the following features.

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