JPH08177862A - Metallic micro-thrust plate and its manufacture - Google Patents

Abstract

PURPOSE: To provide a metallic micro-thrust plate with high dimensional accuracy and geometrical form accuracy and its manufacturing method whereby the plate can be mass-produced at low cost. CONSTITUTION: A metallic micro-thrust plate 11 comprises two or more of metal plates of the same material which are provided with substantially vertical through-hole and/or unpassed hole machined by a press in the plate surface and connected laminatedly by diffusion brazing. It is manufactured by pressing two or more of metal plate frames of the same material so as to from the through-hole 14 and/or unpassed hole, and screw cutting the inner surface of the through-hole 15 and/or unpassed hole located underside. Then the surface of each metal frame is abrasive-machined, each metal plate frame is connected laminatedly by diffusion brazing, and press down several pieces of each type of products from the metal plate frame by pressing, applying heat treatment to each product so as to refine it to a specified hardness, and abrasive-machining the surface again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust bearing for a thrust bearing, which is a type of hydrostatic bearing, and a thin metal plate having through holes and / or non-through holes substantially perpendicular to the plate surface. The present invention relates to a metal-made micro-thrust plate that can be mass-produced at a low cost and a manufacturing method thereof.

[0002]

2. Description of the Related Art Thrust bearings that support the axial load of a rotating shaft are static pressure type bearings having high motion accuracy and rotation accuracy. This is because the lubricating oil film formed between the shaft and the bearing surface has a function of mitigating the influence of the shape error between the shaft and the bearing surface and realizing smooth motion. The thrust plate is a component that is directly connected to the shaft and faces the bearing surface, has a role of receiving a load, and is required to have highly accurate flatness, parallelism, and hardness. As shown in FIG. 8, a double screw stud c is used to fix the thrust plate a to the shaft b, but a double screw stud c is used on the opposite surface.
In order not to expose the end face of the thrust plate a, it is necessary to use the bottomed screw d on the thrust plate a. As a procedure for manufacturing such a thrust plate, first, the prepared hole is drilled so as not to penetrate, and then the bottomed screw is processed. In drilling, strict dimensional control in the depth direction is required in order to avoid the occurrence of protrusions due to penetration or drilling on the back surface. On the other hand, in threading, it is required to cut and cut the tip in advance and manufacture and use a tool having a threaded portion up to the tip surface, and to strictly control the dimensions in the depth direction. Further, in screw processing, it is difficult to discharge cutting powder generated from this, so that the tool frequently breaks during processing, which not only makes automation difficult, but also significantly impairs productivity. This was particularly remarkable in a thin-walled micro thrust plate having a plate thickness of 3 mm or less.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a metal micro thrust plate having high dimensional accuracy and geometric accuracy, and a manufacturing method capable of mass-producing the metal micro thrust plate at low cost.

[0004]

The metal micro-thrust plate according to the present invention comprises two or more sheets of the same material having through holes and / or non-through holes which are substantially perpendicular to the plate surface formed by pressing. A metal plate is laminated and joined by diffusion brazing, and in particular, the metal plate is composed of upper and lower two parts, and the upper part has a non-through hole and / or a non-through hole substantially perpendicular to the plate surface on the upper surface. Or, a through hole is provided, and the lower part is provided with a through hole in which a screw is engraved on the inner surface.
This manufacturing method presses two or more metal plate frames of the same material to form through holes and / or non-through holes, and the through holes and / or non-through holes of the metal frame located below are formed. The inner surface is screwed, the surface of each metal frame is processed with abrasive grains, each metal plate frame is laminated and joined by diffusion brazing, and multiple individual products are pulled out from the metal plate frame by press working to make each product. It is characterized in that a heat treatment is applied to adjust the hardness to a predetermined hardness, and the surface is again processed into abrasive grains.

The metal micro-thrust plate of the present invention will be described in detail below with reference to FIGS. 1 (a) is a perspective view of the metallic micro thrust plate 11, and FIG. 1 (b) is an upper part 12 thereof.
An exploded perspective view of each lower part 13 is shown. 2 (a)-
(C) is a longitudinal sectional view showing a manufacturing process of the metal micro thrust plate 11. 3 and 4 (a) to (c)
FIG. 3A is a vertical cross-sectional view showing a manufacturing process of metal micro-thrust plates 21 and 31 of another embodiment. 1 in each figure
2, 22, 32 are upper parts, 13, 23, 33 are lower parts, 14, 34 are through holes (in each part), 15, 25, 35 are (similar) threaded through holes, 26, 36 Indicates a (similar) hole, 17, 27, 37 indicates burrs, 18, 28, 38 indicate sag, and 29, 39 indicate protrusions. Metal micro-thrust plate 11 ... is alloy tool steel, high speed tool steel, martensitic stainless steel, precipitation hardening stainless steel, etc.
Using the same metal material that can increase the material hardness by heat treatment,
Alternatively, it is manufactured by dividing it into two or more parts according to the size and shape of the non-through hole in the depth direction.

The non-through holes formed on the surface of each metal micro thrust plate 11 are used as holes for inserting a tool when fixing the thrust plate to the shaft. Therefore, the depth of the non-through hole needs to be sufficient to allow the protrusion itself of the tool to withstand the tightening torque of the tool. On the other hand, the non-through hole formed in the lower surface of the thrust plate is used to fix the thrust plate to the shaft with the double-threaded studs, so the depth of the screw is sufficient for fixing the shaft to the double-threaded studs. It is designed so that the fixing strength can be secured. When the thrust plate is manufactured by dividing it into upper and lower parts, the total size of the depth of the non-through holes formed on the surface and the depth of the non-through holes formed on the lower surface is the plate of the thrust plate. When the thickness is exceeded, it is necessary to form the through holes from one surface so as to penetrate one component and reach the other component. The holes communicating between the two parts are arranged so as to come to the same position during stacking, and the diameter of the upper part thereof is made larger by 0.06 to 0.10 mm than the diameter of the lower part. As a result, it is possible to prevent the defective insertion of the protrusion of the fixed tool due to the stacking deviation.

The two parts 12, 13, ... Constituting each of the metal micro thrust plates 11 ... Form a through hole and / or a non-through hole by pressing a metal plate made of the above-mentioned unheated material. Or, after press working, the inner surfaces of these holes are further threaded (16) to be manufactured.
Burrs 17 produced by press working, sag 18 and projections 29 appearing on the opposite surface in correspondence with the non-through holes, and burrs produced by tapping are cut or ground on both sides of each component 12, 13. It is removed by performing grain processing. Since the depth of the penetrating tap is equal to the plate thickness of the metal plate, highly accurate dimensional control can be easily performed with good reproducibility by adjusting the plate thickness. With the above-described method of manufacturing a component, the constituent parts of the metal micro-thrust plate of the present invention can be basically laminated with only two parts. This has a major feature that the number of components is increased by stacking, but the present invention requires a minimum number of components. Unlike through-bottom thread processing, through-thread processing allows cutting powder generated during thread processing to be easily discharged from the back surface. In addition, it is not necessary to stop the progress of the tool at the moment when the tool reaches the bottom of the screw, and the tool may pass through the metal plate, so if the dead end of the tool is ignored, the tool will be damaged or conversely. It is possible to avoid a situation where the number of thread threads is insufficient, which is caused by not advancing to the specified depth. Further, in the case of automating the machining with a bottomed screw, it is necessary to control the machining dimension in the depth direction with high accuracy for the above reason, which requires a large equipment and becomes expensive.
On the other hand, in the through screw processing, the equipment is inexpensive and easy to automate, and therefore the productivity is good.

The parts are pressed in the frame state shown in FIG. A plurality of upper parts 12 having divided through holes 14 and / or non-through holes and lower parts 13 having threaded through holes 15 are provided in each frame 41, 42 at intervals. Placed and designed to stack exactly when stacked. In the product layout in the frames 41 and 42, the upper part 12 and the lower part 13 are arranged such that their burr surfaces face inward when stacked. Therefore, when the lower frame 42 is turned upside down and overlapped with the upper frame 41, the internal patterns thereof completely match. As shown in the enlarged view of FIG. 6A, the upper part 12 is provided with half-moon shaped slits 43 facing each other, and its outer dimension is 0.05 to 0.1 larger than the final withdrawal dimension of the product in the upper frame 41. Designed to be mm smaller so that it can be removed with bridges 44 attached to both ends. This is an escape during the process of product removal after lamination joining. Upper part 12 with such a bridge 44
Burrs, sags, and undulations are removed by grinding both surfaces after pressing. Note that the press processing is shown in FIG.
As shown in FIG. 4, in addition to the through-holes 14 and the non-through holes 26, the grooves extending along the bottom surface substantially perpendicular to the plate surface, that is, with a vertical clearance of about 1 to 2 μm added. (Not shown)
It is also possible to machine simultaneously with this shape, so that the number of parts can be reduced as compared with the case of using another machining method such as wire cutting. The part manufactured by the above method has a hole without a taper or distortion in its cross section, and is excellent in dimensional accuracy, positional accuracy, and mass productivity.

A reference hole 45 for lamination is provided in each frame 41, 42.
It is also possible to provide a reference hole 46 for final pressing.
The reference hole 45 for stacking is a hole for positioning the separately manufactured parts 12 and 13 at the time of stacking, and two or more parts having the same size are machined at positions common to all parts. However, it is not necessary when the temporary assembly at the time of stacking is performed by caulking. The reference hole 46 for press work is formed by laminating the thrust plate 11 and laminating the laminated frame.
Positioning holes for setting in the mold when pulling out from 47 by pressing, 2 at the common position for all frames 41, 42
Process more than one place. Regarding the diameter of the reference hole 46 at the time of this press working, in the lower frame 42 and the upper frame 41, the latter is made larger by about 0.1 mm. This is for preventing the pilot pin (not shown) of the thrust plate pulling-out die from being unable to be inserted into the reference hole 46 of the stacking frame 47 due to stacking deviation.

The frames 41 and 42 are joined by diffusion brazing with a brazing material 48. The brazing material 48 is manufactured by pressing a nickel-based sheet-shaped brazing material into the same shape as the upper frame 41. The lower frame 42, the brazing material 48, and the upper frame 41 are stacked in order, and then fixed by caulking or press-fitting a positioning pin 49 into the stacking reference hole 45. After the lamination and joining, as shown in FIGS. 6B to 6D, the lamination frame 47 is placed on the die 51, and the punch 52 is placed from above.
Then, the upper frame 41 is pulled out so that it becomes the burr surface of the product 50. This makes it possible to reduce the ratio of the shearing force applied to the joint surface and to avoid the risk of peeling from the laminated joint surface, as compared with the case where press-cutting is performed after the components having no escape are laminated and jointed. The burr generated on the removed product 50 of the upper frame 41 is limited to the bridge portion 44 and facilitates the removal in the post-processing. The external dimensions of the product 50 are the external dimensions of the lower part 13. Further, since the burr 57 generated on the lower part 13 does not project in the plate thickness direction of the product 50, it does not need to be removed unless the presence thereof is a problem, and therefore the burr removal step is unnecessary. In principle, the upper part 12 and the lower part 13 are determined by selecting the thicker plate as the lower part 13
Is preferred. The upper part 12 and the lower part 13 are used to secure the thickness of the parts that determine the external dimensions of the product.
If the plate thicknesses are the same or if there is a restriction in use, the more convenient one may be the lower part 13.

Sections of the thrust plate (product) 50 thus obtained are shown in FIGS. 7 (a) and 7 (b). Since the thread is machined to the bottom of the screw 53, the stud 54 can be screwed to the full depth. In addition, around the corner of the bottom surface of the screw 53, the wax 55 is solidified in an R shape, and has a stable shape in terms of strength. It can be said that this is a shape suitable for resisting the force of peeling from the joint surface even when the screwed stud 54 hits the bottom surface of the screw 53. The final abrasive grain processing (after hardness adjustment by heat treatment) after being cut off into individual thrust plates is an excellent method for ensuring plate thickness accuracy, flatness, parallelism, etc. in mass production and has high reproducibility.

[0012]

EXAMPLES Next, specific embodiments of the present invention will be described. As shown in Fig. 5 (a), a stainless steel (SUS420J2) micro thrust plate 11 with a diameter of 5 mm and a thickness of 1.6 mm is used to form a 70 mm long, 50 mm wide, 1.0 mm thick through-hole. Lower frame 42 with holes, 70 mm long,
The upper frame 41 having a horizontal hole of 50 mm and a thickness of 0.6 mm and / or an upper frame 41 having an unperforated hole was divided and designed, and a stainless steel plate was pressed, and the former was further subjected to a through screw process. Each frame 41, 42 should be 5 to 20 mm larger than the finish size in consideration of cutting or abrasive grain finishing in the next process.
% Thick material used. The upper and lower surfaces of each of the frames 41 and 42 are finished by cutting and abrasive processing, or only by abrasive processing, as shown in FIG. Length 70 mm, width 50 mm, plate thickness
0.04mm nickel-based brazing filler metal (material: BNi-7;
JIS Z 3265) is pressed into the same pattern as the upper frame 41, is inserted between the upper frame 41 and the lower frame 42, and is stacked, and then positioned in the stacking reference hole 45 for positioning stainless steel. A pin 49 made of steel was press-fitted. Insert both sides of the laminate with a pressing jig (not shown) into a vacuum furnace, vacuum degree 5 × 10 ^-4 Torr, pressure 10 kgf / cm ² , temperature 1000.
Bonding was performed under conditions of 20 ° C. and 20 minutes.

After joining, the laminated frame 47 was placed on the mold 51 so that the lower frame 42 had a sagging surface, and 15 thrust plates 50 having a diameter of 10 mm were removed by press working.
The thrust plate 50 after pressing was inserted into a vacuum furnace, heated at a vacuum degree of 5 × 10 ⁻⁴ Torr and a temperature of 980 ° C. for 20 minutes, and quenched under air cooling with a nitrogen gas pressure of 700 mmHg. Immediately after the quenching was completed, sub-zero treatment was performed under the conditions of a temperature of -78 ° C and 1 hour. Next, insert the thrust plate 50 into the vacuum furnace and set the vacuum degree to 5
It was heated at × 10 ^-4 Torr and a temperature of 200 ° C for 120 minutes, and tempered under air cooling with a nitrogen gas pressure of 700 mmHg. After the quenching and tempering heat treatment was completed, it was finished by double-sided abrasive grain processing. The plate thickness accuracy of the final product obtained is ± 0.005 mm, the tap depth accuracy is ± 0.03 mm, the depth accuracy of the non-passage hole is ± 0.03 mm, and the positional accuracy between the tap and the non-passage hole is within 0.08 mm. It was The flatness of the abrasive grain surface is 0.4 to 0.8 μm, the parallelism is 0.6 to 0.9 μm,
The hardness was Hv 480 to 505. In this way, it was possible to manufacture a stainless steel micro-thrust plate with a small stacking deviation and a good tap depth accuracy. Table 1 shows the result of comparison between the thus-obtained micro thrust plate according to the present invention and the conventional micro thrust plate.

[0014]

[Table 1]

[0015]

EFFECTS OF THE INVENTION According to the present invention, 1) the component is divided into two components in advance and designed by pressing, so that mass production and reproducibility are excellent. 2) Since the screw is a through process, it is easy to discharge cutting powder,
The tool has a long service life, and the automation of screw processing can be performed easily with relatively inexpensive equipment. Further, since the screw depth is equal to the plate thickness, by controlling the plate thickness, highly accurate depth control can be performed with good reproducibility in mass production. 3) Since the parts are handled as a frame, they are easy to handle, and the smaller the thrust plate is, the more effective it is in removing burrs caused by screwing or non-through hole processing. 4) The screw thread after diffusion brazing is processed to the bottom surface, and the screw part can be screwed in to the bottom surface for use. In addition, since the R-shaped wax reservoir is formed on the bottom surface, the shape resists the force of hitting or peeling the screw component. 5) As a method for finishing the final thickness dimension, flatness, and parallelism satisfactorily, it is possible to suppress variations in mass productivity, reproducibility, and thickness accuracy by performing abrasive grain processing.

[Brief description of drawings]

FIG. 1 shows an example of a thrust plate of the present invention,
(A) is a whole perspective view, (b) is an exploded perspective view of (a).

2 (a) to 2 (c) are vertical cross-sectional views showing machining steps of respective parts and combinations thereof in manufacturing the thrust plate shown in FIG.

3 (a) to 3 (c) are vertical cross-sectional views showing machining steps of respective parts and combinations thereof when manufacturing another thrust plate of the present invention.

4 (a) to 4 (c) are vertical cross-sectional views showing machining steps of respective parts and combinations thereof when manufacturing another thrust plate of the present invention.

5 (a) and 5 (b) are exploded perspective views of a laminated frame and a state after diffusion brazing in a diffusion brazing process of a frame having a plurality of parts for manufacturing the thrust plate shown in FIG. 1, respectively. FIG.

FIG. 6 relates to a step of individually obtaining thrust plates by pressing from the frame after diffusion brazing obtained in FIG. 5, (a) is a plan view showing a state of thrust plates before pressing, and (b) is a plan view. FIG. 3 is a vertical sectional view showing a state at the time of pressing, (c) is a plan view of a thrust plate after pressing, and (d) is a vertical sectional view thereof.

7 (a) and 7 (b) are vertical cross-sectional views showing a state in which a screw is fixed to the thrust plate obtained in FIG. 6, respectively.

FIG. 8 is a vertical cross-sectional view showing a state in which a screw is fixed to a conventional thrust plate.

[Explanation of symbols]

11, 21, 31: Metal micro thrust plate, 12, 2
2, 32: Upper part, 13, 23, 33: Lower part,
14, 34: Through hole, 15, 25, 35: Threaded through hole, 26, 36: Non-through hole, 17, 27, 37, 57: Burr, 18, 28, 38: Sagging, 29, 39: Protrusion, 41: Upper frame, 4
2: Lower frame, 43: Half-moon shaped slit, 44: Bridge, 45: Reference hole for stacking, 46: Reference hole for processing,
47: laminated frame, 48: brazing material,
49: Pin for positioning, 50: Product,
51: Mold, 52: Punch,
53: screw, 54: stud,
55: Definitely. a: Thrust plate,
b: shaft, c: double threaded stud, d: bottomed thread.

Claims (4)

[Claims] 1. A 2 of the same material having through holes and / or non-through holes which are substantially perpendicular to a plate surface obtained by press working.
A metal micro-thrust plate in which one or more metal plates are laminated and joined by diffusion brazing. 2. A metal plate is composed of two upper and lower parts, an upper part having a non-through hole and / or a through hole substantially perpendicular to the plate surface, and a lower part having an inner surface. The metal micro thrust plate according to claim 1, comprising a through hole in which a screw is engraved. 3. A through hole and / or a non-through hole is formed by pressing two or more metal plate frames of the same material, and the through hole and / or the non-through hole of the metal frame located below The inner surface is screwed, the surface of each metal frame is processed with abrasive grains, each metal plate frame is laminated and joined by diffusion brazing, and multiple individual products are pulled out from the metal plate frame by press working to make each product. A method for manufacturing a metal micro-thrust plate, which comprises subjecting a surface to heat treatment to adjust the hardness to a predetermined hardness and then subjecting the surface to abrasive grains again. 4. The method for producing a metal micro-thrust plate according to claim 3, wherein the metal plate frame is made of a material having a melting temperature of 1300 ° C. or higher and whose hardness can be increased by heat treatment.