JP2021127487A - Autofrettage device and autofrettage method - Google Patents

Abstract

To provide an autofrettage device and an autofrettage method capable of reducing an amount of pressurized liquid without enlarging the device.SOLUTION: An autofrettage device K comprises a first fixing member 1 for fixing an upper end w1 of a cylindrical workpiece w, a second fixing member 2 for fixing a lower end w2 of the workpiece w, a first piston 3 for pressing the second fixing member 2 toward the workpiece w, a second piston 4 arranged inside the first piston 3 and to which a pressing member 5 for pressurizing a liquid r in the workpiece w is attached, and volume reduction members 7, 8 between the first fixing member 1 and the second fixing member 2 for reducing the volume of the interior of the workpiece w.SELECTED DRAWING: Figure 1

Description

The present invention relates to an autofrettage processing apparatus and an autofrettage processing method.

Conventionally, when a residual compressive stress is applied to the surface of a workpiece, it is common to modify the surface by using shot peening, cavitation peening, or the like.
For the inner surface of the work piece of the tubular member, a nozzle may be arranged on the inner peripheral surface of the workpiece of the tubular member to perform surface treatment. However, there are cases where the option of arranging the nozzles is not effective depending on the inner diameter of the workpiece and the range of the target surface for surface modification.

In that case, for example, an example is disclosed in which the inner peripheral surface of a workpiece such as a hydrogen container or a common rail is subjected to a "self-tightening" treatment in which a residual compressive stress is applied to a target portion by applying pressure in a sealed environment. There is.
In addition to the above-mentioned examples of workpieces, there are many workpieces having a cylindrical member such as a cylinder or a cloth. Therefore, it is desired to develop an apparatus capable of easily performing autofrettage treatment on a member in which stress concentration is likely to occur.

Patent Document 1 includes a means for filling the inner chamber of a workpiece to be self-tightened with a liquid, a means for closing the inner chamber with pressure, and a means for forming pressure in the inner chamber of the workpiece. The device is disclosed.
In Patent Document 2, the relationship between the internal pressure of the liquid, the hardness of the tubular member which is a workpiece, and the amount of displacement of the tubular member which is a workpiece at a predetermined portion is set in advance, and before the liquid is pressurized / processed. A manufacturing process including a measuring step for measuring and a determination step for determining compressive residual stress based on a dimensional difference after pressurization / processing is disclosed.

Japanese Patent No. 5264756 Japanese Patent No. 5029620

By the way, when the inside of a tubular member which is a workpiece is pressurized, it is necessary to provide a configuration for fixing both the upper and lower sides and the periphery and a configuration for pressurizing in order to seal the workpiece. It also requires a liquid source pump to move the liquid in and out. Therefore, when combined with peripheral devices, the physical space tends to be large, and the device tends to be large. Also, when pressurizing the inner peripheral surface of the tubular member, which is a workpiece, a certain amount of liquid is injected inside. There is a need to. As a result, there is a problem that the liquid inside flows and the amount of pressurized / residual compressive stress applied is unstable.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a self-tightening treatment device and a self-tightening treatment method capable of reducing the amount of liquid to be pressurized without increasing the size of the device.

In order to solve the above problems, the first self-tightening processing apparatus of the present invention has a first fixing member for fixing the upper end of the tubular workpiece and a second fixing member for fixing the lower end of the workpiece. , A first piston that presses the second fixing member toward the workpiece, and a pressing member that is arranged inside the first piston and presses the liquid in the workpiece are attached. It has a volume narrowing member between the second piston and the first fixing member and the second fixing member, which narrows the internal volume of the workpiece.

The second self-tightening treatment method of the present invention is to press the first fixing member, the second fixing member, the first piston, and the second piston to which the plunger arranged inside the first piston is attached. It is a self-tightening method of a self-tightening processing device provided with a member and provided with a first inflow port and a second inflow port, and is a self-tightening processing method with one end of a tubular workpiece having a narrow volume member inside. A step of fixing the other end portion with the first and second fixing members, a step of inflowing liquid from the first inflow port and raising the first piston, and the second inflow port. It includes a step of inflowing a liquid from the piston to raise the second piston and a step of the pressing member pressurizing the liquid inside the workpiece.

According to the present invention, it is possible to provide a self-tightening treatment device and a self-tightening treatment method capable of reducing the amount of liquid to be pressurized without increasing the size of the device.

The vertical sectional view of the autofrettage processing apparatus which concerns on embodiment of this invention. A perspective view of the first fixing member as viewed from below. A perspective view of the second fixing member as viewed from above. (A) is a perspective view of the cylindrical member, and (b) is a perspective view of the cylindrical member. The schematic diagram of the liquid circuit S. (a) and (b) are schematic cross-sectional views showing the processing procedure of the autofrettage processing apparatus. (a) and (b) are schematic cross-sectional views showing the processing procedure of the autofrettage processing apparatus. (a), (b), and (c) are schematic cross-sectional views showing a processing procedure of the autofrettage processing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 shows a vertical cross-sectional view of the autofrettage processing device K according to the embodiment of the present invention.
The autofrettage processing device K of the embodiment is a device that applies compressive residual stress to the inner surface w4 of the tubular workpiece w.
The autofrettage processing device K has a substantially columnar shape, and has a first fixing member 1, a second fixing member 2, a first piston 3 (3a, 3b), a second piston 4, and a plunger. 5 and a cylinder 6 are provided.

The first fixing member 1 and the second fixing member 2 are members for fixing the tubular workpiece w to the autofrettage processing device K.
The first fixing member 1 fixes the upper part of the tubular workpiece w. The second fixing member 2 fixes the lower part of the tubular workpiece w.

FIG. 2 shows a perspective view of the first fixing member 1 as viewed from below.
The first fixing member 1 includes a disk portion 1a, a cylindrical portion 1b, an annular pressure step portion 1c that continues to the central side of the columnar portion 1b, and a columnar positioning portion that continues to the central side of the pressure step portion 1c. It has 1d and.
The positioning portion 1d of the first fixing member 1 is fitted to the upper inner circumference of the tubular workpiece w to position the upper side of the workpiece w.
The pressure step portion 1c of the first fixing member 1 is pressed against the upper end edge w1 of the workpiece w.
The diameter 1d1 of the positioning portion 1d has a dimension slightly smaller than the inner diameter t2 (see FIG. 1) of the workpiece w due to the fitting relationship. The diameter 1c1 of the pressure step portion 1c has a pressure larger than the fluid pressure inside the workpiece w at the pressure step portion 1c, and has an area such that the indentation of the work piece w fits in a predetermined amount (details will be described later). Will be decided.
The diameter 1b1 of the cylindrical portion 1b is determined to be larger than the diameter 1c1 of the pressure step portion 1c and smaller than the innermost inner diameter of the upper guide guide 15 in order to avoid contact with the upper guide guide 15.

As shown in FIG. 1, an upper guide guide 15 is arranged between the first fixing member 1 and the upper end edge w1 of the workpiece w. The upper guide guide 15 is a member that guides the first fixing member 1 with respect to the workpiece w.
The upper guide guide 15 is an annular member. The upper guide guide 15 is preferably made of metal, but may be made of a material other than metal, such as a resin, as long as it can serve as a guide.
The upper guide guide 15 has a tubular portion 15a and a donut-shaped ring-shaped disc portion 15b having holes 15c continuously inside the tubular portion 15a.
The lower inner diameter 15n1 of the upper guide guide 15 has a diameter slightly larger than the outer diameter w12 of the workpiece w. The upper inner diameter 15n2 of the upper guide guide 15 has a diameter slightly larger than the outer diameter 1g1 of the first fixing member 1.

The tubular portion 15a is formed with air bleeding holes 15d1 and 15d2 that are continuous inside and outside the tubular portion 15a.
The air vent holes 15d1 and 15d2 are formed symmetrically in the vertical direction (vertical direction in FIG. 1). Therefore, if the lower inner diameter 15n1 and the upper inner diameter 15n2 of the upper guide guide 15 are set to the same dimensions, the upper guide guide 15 can be used without vertical direction.

FIG. 3 shows a perspective view of the second fixing member 2 as viewed from above.
The second fixing member 2 has a disk portion 2a having a large diameter, a cylindrical positioning portion 2b having a diameter smaller than that of the disk portion 2a, and an annular pressure step extending radially outward to the cylindrical positioning portion 2b. It has a part 2c. An insertion hole 2d through which the plunger 5 is inserted is formed in the center of the second fixing member 2.
The cylindrical positioning portion 2b of the second fixing member 2 is fitted to the lower inner circumference of the tubular workpiece w to position the lower side of the workpiece w.
The pressure step portion 2c of the second fixing member 2 is pressed against the lower end edge w2 (see FIG. 1) of the workpiece w.
The diameter 2b1 of the positioning portion 2b has a dimension slightly smaller than the inner diameter t2 (see FIG. 1) of the workpiece w due to the fitting relationship. The diameter 2c1 of the pressure step portion 2c has a pressure larger than the fluid pressure inside the workpiece w at the pressure step portion 2c, and has an area such that the indentation of the work piece w fits in a predetermined amount (details will be described later). Will be decided.

As shown in FIG. 1, a lower guide 16 is arranged between the second fixing member 2 and the lower end edge w2 of the workpiece w. The lower guide guide 16 is a member that guides the second fixing member 2 and the workpiece w with respect to the first upper piston 3a.
The lower guide guide 16 has a tubular shape. Therefore, the inner diameter 16n of the lower guide guide 16 is the outer diameter 3a11 of the fitting convex portion 3a6 of the first upper piston 3a, the outer diameter w11 of the workpiece w, and the outer diameter 2d1 of the second fixing member 2 (see FIG. 3). ) Has slightly larger dimensions.
The lower guide guide 16 is preferably made of metal, but may be made of a material other than metal, such as a resin, as long as it can serve as a guide.

Air vent holes 16a, 16b, 16c are inserted through the lower guide guide 16. The air bleeding holes 16a and the air bleeding holes 16c are formed symmetrically in the vertical direction (vertical direction in FIG. 1). Therefore, the lower guide guide 16 can be used without vertical direction.
Inside the tubular workpiece w fixed by the first fixing member 1 and the second fixing member 2, a cylindrical member which is a narrow volume member is used in order to narrowly adjust the internal volume of the workpiece w. 7 and a cylindrical member 8 are arranged.
Since there are rigid members (7, 8) inside the workpiece w to which a high load is applied, the amount of the treatment liquid (liquid) is reduced, and the target pressure is reached with a smaller stroke of the plunger 5.
That is, since the columnar member 8 is columnar and has a large volume, the amount of the treatment liquid (liquid) can be significantly reduced. Further, it is suitable for greatly reducing the stroke amount of the plunger 5.
Since the cylindrical member 7 is tubular and has a small volume, it is suitable for reducing the amount of the treatment liquid (liquid) by a small amount. Further, the cylindrical member 7 is suitable for reducing the stroke amount of the plunger 5 by a small amount.

FIG. 4A shows a perspective view of the cylindrical member 7.
The cylindrical member 7 has a cylindrical shape having an insertion hole 7a for flowing a liquid in the center. The insertion hole 7a has an inner diameter t1 through which oil flows and the plunger 5 is inserted.
A groove 7b for flowing a liquid is formed at one end of the cylindrical member 7 in the radial direction. Grooves 7b may be provided at both ends of the cylindrical member 7.

FIG. 4B shows a perspective view of the cylindrical member 8.
The cylindrical member 8 has a cylindrical shape.
The cylindrical member 8 is formed with an insertion hole 8a for flowing a liquid in the center so as to penetrate in the axial direction (longitudinal direction). The insertion hole 8a has a diameter smaller than the inner diameter t1 of the insertion hole 7a of the cylindrical member 7.
A groove 8b for flowing a liquid is formed at one end of the cylindrical member 8 in the radial direction. The grooves 8b may be provided at both ends of the cylindrical member 8.
At least one of the cylindrical member 7 and the cylindrical member 8 is used inside the workpiece w. FIG. 1 shows an example in which the cylindrical member 7 and the two cylindrical members 8 are used.

<First piston 3>
As shown in FIG. 1, the first piston 3 has a role of fixing the workpiece w sandwiched between the first fixing member 1 and the second fixing member 2 above the autofrettage processing device K. Further, the first piston 3 has a role of moving the vertically moving plunger 5 and the second piston 4 described later in the vertical direction.
The first piston 3 includes an upper first upper piston 3a and a lower first lower piston 3b.

The first upper piston 3a has a bottomed cylindrical shape having a tubular portion 3a2 in which a space 3a1 having an open lower portion is formed. An insertion hole 3a3 for guiding the plunger 5 that moves up and down in the vertical direction is formed in the center of the first upper piston 3a.
A ventilation hole 3a4 through which air passes is penetrated through the tubular portion 3a2 toward the side.
A fitting recess 3a5 is formed in the lower portion of the tubular portion 3a2 of the first upper piston 3a. An annular fitting convex portion 3a6 is formed on the upper portion of the first upper piston 3a so as to project upward.

The first lower piston 3b is fixed to the fitting recess 3a5.
The first lower piston 3b has a substantially bottomed cylindrical shape having a tubular portion 3b2 in which an internal space 3b1 having an open lower portion is formed. A thick ring portion 3b7 is formed in the lower portion of the tubular portion 3b2.
The cylinder portion 3b2 in which the internal space 3b1 is formed plays the role of a cylinder for sliding the second piston 4. Therefore, below the first lower piston 3b, a closing member 3h that closes the internal space 3b1 of the first lower piston 3b is fixed with a bolt or the like (not shown).

Above the first lower piston 3b, a second inflow port 3b3 through which the liquid flows into the internal space 3b1 between the first lower piston 3b and the second piston 4 and a liquid entering the internal space 3b1. A second discharge port 3b4 is formed.
The first lower piston 3b has a first flow path 3b5 extending in the longitudinal direction following the second inflow port 3b3, an internal space 3b1 inside the cylinder portion 3b2 following the first flow path 3b5, and the outside of the cylinder portion 3b2. A second flow path 3b6 communicating with the space is formed.

<Second piston 4>
The second piston 4 is configured to slide up and down in the internal space 3b1 in the tubular portion 3b2 of the first lower piston 3b.
The second piston 4 has a substantially columnar shape having a first small diameter portion 4a, a large diameter portion 4b, and a second small diameter portion 4c.
A long rod-shaped plunger 5 having an outer diameter t3 is fixed to the upper portion of the second piston 4.

The large diameter portion 4b of the second piston 4 slides up and down in the tubular portion 3b2 of the first lower piston 3b.
A cylinder 6 on which the first lower piston 3b slides is provided around the first lower piston 3b.

<Cylinder 6>
The cylinder 6 has a tubular shape.
The cylinder 6 has a body portion 6a, a sliding portion 6b, and a flange 6c.
Inside the body portion 6a, a sliding space 6d (6d1, 6d2) (see FIGS. 6 (a) and 7 (a)) on which the annular portion 3b7 of the first lower piston 3b slides is formed. There is.
The cylinder 6 is penetrated by a first inflow port 6e1 in which the liquid flows into the sliding space 6d1 and a first discharge port 6e2 in which the liquid inside the sliding space 6d2 flows out.

The flange 6c of the cylinder 6 is fixed to a base 12 that closes the sliding space 6d from below with bolts or the like (not shown).
Here, the inner diameter t1 of the cylindrical member 7 (see FIG. 4A) is smaller than the inner diameter t2 of the workpiece w (see FIG. 1) and larger than the outer diameter t3 of the plunger 5 (see FIG. 1). As a result, the cylindrical member 7 can be put inside the workpiece w. Further, the plunger 5 can move in the cylindrical member 7.
<Liquid circuit S>

FIG. 5 shows a schematic diagram of the liquid circuit S.
The liquid circuit S is a device that supplies the liquid to the autofrettage processing device K and discharges the liquid.
In the liquid circuit S, the pump P, the valves s11 to s14, the pressure gauge s21, and the pressure sensor s22 are connected by a pipe line k. k is a generic code for the pipeline.
The pump P supplies the liquid to the autofrettage processing device K via the pipeline k, and discharges the liquid from the autofrettage processing device K.

The valves s11 to s14 open and close the pipeline k.
The pressure gauge s21 measures the pressure of the liquid in the conduit k. The pressure sensor s22 is a pressure sensor with a built-in amplifier.
The pipeline k1 is connected to the first inflow port 6e1 of the cylinder 6. The pipeline k2 is connected to the second inflow port 3b3 of the first lower piston 3b. The pipeline k3 is connected to the first discharge port 6e2 of the cylinder 6. The pipeline k4 is connected to the second discharge port 3b4 of the first lower piston 3b.

The liquid from the pump P flows into the inside of the autofrettage processing device K from the first inflow port 6e1 and the second inflow port 3b3. Further, the liquid that has flowed into the self-tightening processing device K is discharged to the liquid circuit S from the first discharge port 6e2 and the second discharge port 3b4.
Specifically, as described below, the liquid is introduced from the liquid circuit S into the self-tightening processing device K. Further, the liquid inside the autofrettage processing device K is discharged to the liquid circuit S.
In order to move the first piston 3 and the second piston 4 upward, the sliding space 6d1 below the first lower piston 3b inside the cylinder 6 from the first inflow port 6e1 of the cylinder 6 (FIG. 7). The liquid is allowed to flow into (see (a)), and the liquid in the sliding space 6d2 (see FIG. 6 (a)) above the first lower piston 3b inside the cylinder 6 is introduced from the first discharge port 6e2 of the cylinder 6. Discharge.

Further, in order to move the second piston 4 upward from the first piston 3, the first piston 3 and the second piston 4 are moved from the second inflow port 3b3 of the first lower piston 3b shown in FIG. The liquid is made to flow into the internal space 3b11 between the piston and the liquid, and the liquid is discharged from the second discharge port 3b4 of the first lower piston 3b.
As a result, the first piston 3 and the second piston 4 move upward to be in the state shown in FIG. 7 (b).
On the other hand, when the second piston 4 is lowered with respect to the first piston 3, as shown in FIG. 8 (b) described later, the second piston 4 is passed through the second discharge port 3b4 of the first lower piston 3b. , The liquid is allowed to flow into the internal space 3b12 (see FIG. 1) between the first piston 3 and the second piston 4, and the internal space 3b11 (FIG. 1) between the first piston 3 and the second piston 4 is allowed to flow. 1) is discharged from the second inflow port 3b3 of the first lower piston 3b.

Further, when lowering the first piston 3 and the second piston 4, the liquid flows into the sliding space 6d2 above the first lower piston 3b from the first discharge port 6e2 of the cylinder 6. The liquid in the sliding space 6d1 below the first lower piston 3b is discharged from the first inflow port 6e1 of the cylinder 6.

<Processing procedure of autofrettage processing device K>
Next, the processing procedure of the autofrettage processing device K will be described.
6 (a) to 8 (c) show the processing procedure of the autofrettage processing device K.

As shown in FIG. 6A, the cylinder 6 is fixed to the base 12. A first piston 3 through which a second piston 4 to which a plunger 5 is attached is inserted is fitted in the cylinder 6.
The lower guide guide 16 is fitted into the outer peripheral portion of the fitting convex portion 3a6 of the first piston 3 from above.
The insertion hole 2d is inserted into the plunger 5, and the second fixing member 2 is fitted from above. After that, the workpiece w is fitted into the inner peripheral portion of the lower guide guide 16 and the outer peripheral portion of the cylindrical positioning portion 2b (see FIG. 3) of the second fixing member 2 from above.

In this state, a predetermined amount of liquid r such as oil is put into the inner peripheral portion w4 of the workpiece w.
Subsequently, as shown in FIG. 6B, the cylindrical member 7 and the cylindrical member 8 are arranged in the workpiece w. Specifically, a cylindrical member 7 (see FIG. 4A) and two cylindrical members 8 (FIG. 4B) are inserted into the inner peripheral portion w4 of the workpiece w.
After that, the upper guide guide 15 is fitted into the outer peripheral portion w5 of the workpiece w. Then, the positioning portion 1d (see FIG. 2) of the first fixing member 1 is inserted into the inner peripheral portion w4 of the workpiece w using the tubular portion 15a (see FIG. 1) of the upper guide guide 15 as a guide, and the first The fixing member 1 of the above is arranged.
Tolerances are provided for the upper guide guide 15, the lower guide guide 16, the first fixing member 1, the second fixing member 2, and the fitting convex portion 3a6 of the first upper piston 3a, respectively.
The first fixing member 1 follows the upper guide guide 15, and the second fixing member 2 and the fitting convex portion 3a6 of the first upper piston 3a follow the lower guide guide 16, so that the surface pressure due to the eccentric load is followed. (Each contact area between the workpiece w and the pressure step portions 1c and 2c) is pressed.
Further, the upper guide guide 15 and the lower guide guide 16 also have a role of preventing scattering when the treatment liquid (liquid) inside the workpiece w leaks.

Subsequently, as shown in FIG. 7A, a liquid flows into the sliding space 6d1 below from the first inflow port 6e1 of the cylinder 6, and the first piston 3, the second piston 4, and the workpiece w , The first fixing member 1 and the like are raised. At this time, the liquid in the sliding space 6d2 (see FIG. 6B) above the cylinder 6 is discharged from the first discharge port 6e2 of the cylinder 6.
.. Then, the first fixing member 1 comes into contact with the contact member 22 fixed to the ceiling 21. With this, the workpiece w is fixed to the first fixing member 1 and the second fixing member 2.

Subsequently, as shown in FIG. 7 (b), the liquid 1 is introduced from the second inflow port 3b3 of the first lower piston 3b into the internal space 3b11 (internal space 3b11) between the first piston 3 and the second piston 4. (See Fig. 1). Then, the plunger 5 fixed to the second piston 4 rises.
Then, as shown in FIG. 8A, the inner circumference of the cylindrical member 7 is formed by allowing the liquid r to flow in from the first inflow port 6e1 of the cylinder 6 and the second inflow port 3b3 of the first lower piston 3b. The surface 7a and the outer peripheral surface 7c (see FIG. 4A), the outer peripheral surface 8c of the cylindrical member 8 (see FIG. 4B), and the inner peripheral surface w4 of the workpiece w (see FIG. 6A) were filled. Pressurize the liquid r.

As a result, the liquid r inside the workpiece w presses the inner peripheral portion w4 of the workpiece w, and the autofrettage process is performed. The inner peripheral surface 7a and the outer peripheral surface 7c (see FIG. 4A) of the cylindrical member 7 and the outer peripheral surface 8c (see FIG. 4B) of the cylindrical member 8 are self-tightened in a state of being covered with liquid (oil). Perform processing.
The first fixing member 1 and the second fixing member 2 are contact members fixed to the workpiece w, the first piston 3, and the ceiling 21 as the piston mechanism (3, 4) rises. It is fixed to 22. The cylindrical portion 1d and the pressure step portion 1c (see FIG. 2) of the first fixing member 1 and the cylindrical positioning portion 2b and the pressure step portion 2c (see FIG. 3) of the second fixing member 2 are included in the workpiece w. By putting a plug on the peripheral surface w4, the sealing property is improved. In this state, the plunger 5 presses the liquid r inside the workpiece w.

The principle of residual compressive stress applied by self-tightening is that when pressure is applied to the inner peripheral surface w4 of the workpiece w, the diameter expands according to the pressure, and stress exceeding the yield point is applied to the inner diameter. At the timing, it yields in order from the inner peripheral surface w4. The part of the inner peripheral surface w4 that has yielded and plastically deformed at the timing of decompression cannot be completely restored, and the outer part of the inner peripheral surface w4 that is elastically deformed without yielding is elastically restored. Since it tries to return, the force (compressive stress) that the elastic region pushes the plastic region inward remains in the vicinity of the inner peripheral surface w4.

Further, the upper end surface w1 (see FIG. 1) and the lower end surface w2 of the first fixing member 1 and the second fixing member 2 and the workpiece w have width dimensions (diametrical dimensions) set based on the calculation. As a result, when the liquid r is pressurized, the contact portions between the first fixing member 1 and the second fixing member 2 and the workpiece w (upper / lower end surfaces w1, w2 and the first fixing member 1 of the workpiece w). The pressure generated in the pressure step 1c (see FIG. 2) and the pressure step 2c (see FIG. 3) of the second fixing member 2) is slightly higher than the pressure of the liquid r inside the workpiece w. I'm adjusting. As a result, the contact portions (upper / lower end surfaces w1, w2 of the workpiece w, the pressure step portion 1c of the first fixing member 1 (see FIG. 2), and the pressure step portion 2c of the second fixing member 2 (see FIG. 3). By minimizing the deformation of)), the fixing member (1, 2), the workpiece w, the cylindrical member 7, and the cylindrical member 8 can be easily disassembled as described later.

Here, the pressure of the entire liquid circuit S is controlled by inflowing and outflowing the liquid from the liquid supply source (pump P) into the same circuit, and the pressure is excessively increased to the workpiece w in the step of stepping up and down. It is possible to prevent the generation of stress.
The pressurization time differs depending on the pressurization target (for example, the workpiece w) and the pressurization area of the pressurization target (for example, the inner peripheral surface w4 of the work piece w). That is, the pressure required for appropriate treatment is changed according to the pressure target and the pressure area.

Subsequently, as shown in FIG. 8B, the liquid r is sequentially discharged to the liquid circuit S from the first inflow port 6e1 of the cylinder 6 and the second inflow port 3b3 of the first lower piston 3b. The second and first pistons 4 and 3 descend.

Then, as shown in FIG. 8C, the self-tightening process is completed by removing the first fixing member 1 and the upper guide guide 15 and taking out the cylindrical member (7, 8) from the work piece w.
The result of the self-tightening process is determined by the amount of displacement of the inner peripheral surface w4 of the workpiece w.
The contact portion between the deformed fixing member (1, 2) and the upper and lower end surfaces w1 and w2 of the workpiece w is autofrettage-treated, and then the target portion (near the upper and lower end surfaces w1 and w2 of the workpiece w) is cut off. There is.

According to the above configuration, by having the columnar tip portions (1d, 2b) in the fixing member (1, 2), the sealing property in the workpiece w can be ensured, and the two-stage piston (3, 4) By operating the inflow and outflow of the liquid flowing into the inside by one liquid circuit S and the pump P, the pressure of the entire liquid circuit S is controlled, and excessive stress is applied to the workpiece w in the step of stepping up and down. It can be suppressed from occurring. Further, by using one liquid supply source, the fluid in the apparatus can be stably controlled.

Further, by arranging the cylindrical member 7 and the cylindrical member 8 in the workpiece w, the amount of the liquid r can be reduced and the influence of the compressibility of the liquid r can be reduced. In addition, since the amount of fluid discharged after the autofrettage treatment can be reduced, the cleaning property of the device and the labor for maintenance are reduced.

By dividing into the first and second inflow ports 6e1 and 3b3, the base fixing is carried out by the movement in the first cylinder (6), and the movement of the second cylinder (3, 4) is supplementary. Can be fixed. Therefore, multi-layered fixing can be realized, and highly accurate sealing performance can be ensured.
Further, by adopting a two-stage piston (3, 4) structure, the piston is in a contracted state in normal times. Therefore, the capacity of the self-tightening processing device K in the installation space is good.

<< Other Embodiments >>
1. 1. In the above embodiment, the cylindrical member 7 and the cylindrical member 8 are exemplified as the volume narrowing member, but the volume narrowing member has a shape having a polygonal cross section other than the cylindrical shape (cylindrical member 7) if it is cylindrical. It may be any cylindrical shape such as a shape having a cross section having a curvature and a shape having a cross section having a partial curvature.
If the member has a narrow volume, it has a column shape having a polygonal cross section other than the columnar shape (cylindrical member 8), a column shape having a curved cross section, and a cross section having a partial curvature. Any pillar shape such as a pillar shape may be used. As for the pillar shape, it is preferable to provide an oil passage in the center, but an oil passage may be provided in a part other than the center. Further, the pillar shape may be configured without providing an oil passage.

2. In the autofrettage processing device K of the above embodiment, the case where both the upper guide guide 15 and the lower guide guide 16 are provided is illustrated, but the upper guide guide 15 and the lower guide guide 16 may not be used, and the upper guide guide 16 may not be used. 15 or the lower guide guide 16 may be used.

3. 3. The upper guide guide 15 of the embodiment has a configuration of a first positioning with respect to the workpiece w and a second positioning with respect to the first fixing member 1, and the first fixing with respect to the workpiece w. If the member 1 can be guided, a shape other than the illustrated upper guide guide 15 may be adopted. For example, the upper guide guide 15 may position the first fixing member 1 by using the outer diameter of the cylindrical portion 1b of the first fixing member 1.

4. Further, the lower guide guide 16 of the embodiment has a configuration of a first positioning with respect to the workpiece w and a second positioning with respect to the second fixing member 2, and the second positioning with respect to the workpiece w. If the fixing member 2 of the above can be guided, a shape other than the illustrated lower guide guide 16 may be adopted.
For example, the lower guide guide 16 has a short tubular shape related to the second fixing member 2 and the workpiece w, and has a flat upper surface shape by eliminating the fitting convex portion of the first upper piston 3a. Then, the second fixing member 2 is placed on the first upper piston 3a by guiding the inner peripheral surface thereof with the plunger 5. Then, the lower guide guide 16 is placed around the first upper piston 3a using the inner peripheral surface thereof, and the outer peripheral surface of the workpiece w is guided by the inner peripheral surface of the lower guide guide 16 to guide the workpiece w. It may be configured to be arranged.

5. It should be noted that the configurations described in the above-described embodiments describe the examples of the present invention, and various configurations are possible within the scope of the claims.

w Workpiece w1 Upper end w2 Lower end 1 First fixing member 1c Pressure step (first tip)
2 Second fixing member 2c Pressure step part (second tip part)
3 First piston 3b11 internal space (internal space of the first and second pistons)
3b3 2nd inflow port 3b4 2nd discharge port 4 2nd piston 5 Plunger (pressing member)
6 Cylinder 6d Sliding space (internal space between the cylinder and the first piston)
6e1 1st inflow port 6e2 1st outlet (exhaust port)
7 Cylindrical member (narrow volume member, tubular member)
7a, 8a Insertion hole (hole)
7b, 8b groove 8 Cylindrical member (narrow volume member, columnar member)
15 Top guide guide (top guide member)
16 Lower guide (lower guide member)
K Autofrettage processing device P Pump (liquid source)
S Liquid circuit (liquid source)
t1 Inner diameter of cylindrical member t2 Inner diameter of workpiece t3 Outer diameter of plunger

Claims (12)

A first fixing member for fixing the upper end of the tubular workpiece,
A second fixing member for fixing the lower end of the workpiece and
A first piston that presses the second fixing member toward the workpiece side, and
A second piston, which is arranged inside the first piston and to which a pressing member for pressing the liquid in the workpiece is attached.
An autofrettage processing device between a first fixing member and a second fixing member, which has a volume narrowing member that narrows the internal volume of the workpiece. In the autofrettage processing apparatus according to claim 1.
A first inflow port for liquid to flow into the internal space between the cylinder in which the first piston moves internally and the first piston,
A second inflow port for liquid to flow into the internal space between the first piston and the second piston,
An autofrettage processing device having a discharge port for discharging the liquid. In the autofrettage processing apparatus according to claim 1 or 2.
The autofrettage processing apparatus, wherein the first fixing member and the second fixing member have a first tip portion and a second tip portion, which are contact surfaces with the workpiece, respectively. .. In the autofrettage processing apparatus according to any one of claims 1 to 3.
An autofrettage processing device characterized in that the inner diameter of the cylindrical member, which is the narrow volume member, is smaller than the inner diameter of the workpiece and larger than the outer diameter of the plunger. In the autofrettage processing apparatus according to claim 2.
The first inflow port and the second inflow port are self-tightening processing devices, characterized in that liquid is supplied from one liquid supply source. In the autofrettage processing apparatus according to any one of claims 1 to 5.
The autofrettage processing device, wherein the volume narrowing member has at least one of a tubular member and a columnar member. In the autofrettage processing apparatus according to any one of claims 1 to 6.
The autofrettage processing device, wherein the volume narrowing member has a groove or a hole through which the liquid flows in the longitudinal direction or the radial direction of the workpiece. In the autofrettage processing apparatus according to any one of claims 1 to 7.
It is characterized by having at least one of an upper guide member that guides the first fixing member to the work piece and a lower guide member that guides the work piece to the second fixing member. Autofrettage processing device. It includes a first fixing member, a second fixing member, a first piston, and a second piston to which a pressing member arranged inside the first piston is attached, and has a first inflow port and a second. It is a self-tightening method of a self-tightening treatment device provided with an inflow port.
A step of fixing one end and the other end of a tubular workpiece having a narrow volume member inside with the first and second fixing members.
A step of inflowing a liquid from the first inflow port and raising the first piston, and
A step of inflowing a liquid from the second inflow port and raising the second piston, and
A self-tightening process method comprising the step of pressurizing the liquid inside the workpiece by the pressing member. In the autofrettage processing method according to claim 9.
The autofrettage treatment method, wherein the narrow volume member has at least one of a tubular member and a columnar member. In the autofrettage processing method according to claim 9 or 10.
The autofrettage treatment method, wherein the volume narrowing member has a groove or a hole through which the liquid flows in the longitudinal direction or the radial direction of the workpiece. In the autofrettage processing method according to any one of claims 9 to 11.
The autofrettage processing device has an upper guide member and a lower guide member, and has an autofrettage processing device.
A step of guiding and arranging the workpiece with respect to the second fixing member using the lower guide member, and
A self-tightening processing method comprising a step of guiding and arranging the first fixing member with respect to the workpiece using the upper guide member.

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