JP5533717B2 - Metal body manufacturing method, metal body and fuel supply pump - Google Patents

Description

  The present invention mainly relates to a method of manufacturing a metal body, and more particularly to a method of manufacturing a metal body suitable for forming a pressurizing chamber of a fuel supply pump that supplies fuel to an internal combustion engine.

Conventionally, for example, in a fuel supply pump 100 that supplies high-pressure fuel to an internal combustion engine via a pressure accumulating vessel such as a common rail, the metal body 101 forms a fuel pressurizing chamber 102 as shown in FIG. It is incorporated as one of the parts.
Here, the metal body 101 includes a cylindrical first space 103 and a cylindrical second space 104 that opens to the side wall surface of the first space 103 and connects to the first space 103. The opening edge 105 of the second space 104 is convex (see, for example, Patent Document 1).

  In the fuel supply pump 100, the metal body 101 slidably supports and accommodates the plunger 107 in the first space 103, so that a part of the first space 103 is liquid-tightly partitioned by the plunger 107. Thus, the fuel pressurizing chamber 102 is formed and the plunger 107 is reciprocated in the axial direction by the cam mechanism 108 to change the volume of the pressurizing chamber 102. In addition, the metal body 101 accommodates a check valve 111 including a valve body 109 and a spring 110 in the second space 104. The check valve 111 reduces the volume of the pressurizing chamber 102 and pressurizes the pressurizing chamber. When the fuel pressure of 102 is increased to a predetermined valve opening pressure or higher, the valve is opened so that the fuel flows out from the pressurizing chamber 102.

  For this reason, in the fuel supply pump 100, when the pressurization chamber 102 expands and the fuel pressure in the pressurization chamber 102 is reduced due to the movement of the plunger 107 toward one end in the axial direction, the fuel is supplied to the pressurization chamber 102. Is inhaled and flows in. When the plunger 107 moves toward the other end in the axial direction, the pressurizing chamber 102 is contracted and the fuel pressure in the pressurizing chamber 102 is increased to exceed the valve opening pressure of the check valve 111. Fuel is discharged from the chamber 102 and flows out.

  As described above, according to the fuel supply pump 100, the fuel pressure is repeatedly increased and decreased in the pressurizing chamber 102, and the stress load is repeatedly concentrated on the opening edge 105. Therefore, the metal body 101 including the opening edge 105 needs to be used as a component of the fuel supply pump 100 after improving the pressure resistance.

By the way, as a means for increasing the pressure resistance of the metal body 101, the following method can be considered.
First, a method of increasing the hardness of the metal body 101 by performing carburizing treatment and heat treatment on the metal body 101 can be considered. Further, a method is conceivable in which the opening edge 105 is subjected to processing such as rounding or chamfering to reduce the convexity of the opening edge 105 and make the opening edge 105 less likely to concentrate stress. Furthermore, a method of adopting high-grade steel as the material of the metal body 101 or increasing the surface roughness can be considered.

  However, when the fuel supply pump 100 is applied to an accumulator fuel supply device, the discharge pressure exceeds 200 MPa, and further improvement in the discharge pressure is expected in the future. Therefore, with respect to the opening edge 105 of the metal body 101, a further method for improving pressure resistance is required.

JP 2000-240531 A

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to form a cylindrical first space and a cylindrical opening that opens in a side wall surface of the first space and connects to the first space. An object of the present invention is to provide a pressure resistance improving method capable of increasing the pressure resistance of an opening edge in a metal body provided with a second space and having a convex opening edge of the second space with respect to the first space.

[Means of Claim 1]
According to the means of claim 1, the metal body includes a cylindrical first space and a cylindrical second space that opens in a side wall surface of the first space and connects to the first space, and the first space. The opening edge of the second space with respect to is convex.
The metal body manufacturing method further includes a pressure applying step for increasing the pressure resistance of the opening edge, and the pressure applying step includes a press-fitting jig having a rigidity equal to or higher than the rigidity of the metal body in the first space and the second space. A press-fitting process for press-fitting into at least one of the spaces, a heat-treating process for carburizing the metal body with the press-fitting jig press-fitted at the same time, and a drawing process for extracting the press-fitting jig from the metal body after the heat treatment process And have.
Furthermore, the opening edge has a pressure-resistant requirement part that needs to improve the pressure resistance against repeated flow of fluid into and out of the first space and the second space. Even in this state, it is exposed to the first space and the second space.

Thereby, the pressure | voltage resistance of an opening edge can be improved. The mechanism that can increase the pressure resistance of the opening edge is not clear, but is presumed as follows.
First, a portion (hereinafter referred to as a press contact surface portion) that receives pressure contact on the surface of the press fit jig is expanded and pulled out of the side wall surface that forms a space that has been press fit by the press fit jig.

Next, when the metal body is heat-treated in a state where the press-fitting jig is press-fitted, a portion of the press-fitting surface portion (hereinafter referred to as a non-press-contact surface portion) that is not subjected to press-contact on the press-fitting jig surface due to a change in the metal structure The tissue wraps around and the non-pressure contact surface is compressed. Then, by pulling out the press-fitting jig from the metal body after the heat treatment, the tension of the press contact surface portion is released and compressive residual stress is applied to the non-press contact surface portion.
Thus, the cylindrical first space and the cylindrical second space that opens on the side wall surface of the first space and connects to the first space are provided, and the opening edge of the second space with respect to the first space is convex. In the formed metal body, the pressure resistance of the opening edge can be increased.

In the heat treatment process, carburization is performed simultaneously.
Thereby, a non-pressure-contact surface part hardens | cures by a carburizing process among the side wall surfaces which form 1st, 2nd space. For this reason, the hardness of an opening edge can be raised and pressure | voltage resistance can be improved further.

Furthermore, the opening edge has a pressure-resistant requirement part that needs to improve the pressure resistance against repeated flow of fluid into and out of the first space and the second space. Even in this state, it is exposed to the first space and the second space.
Thereby, since the formation surface of a pressure | voltage resistant request | requirement part can be reliably included in a non-pressure-contact surface part, the pressure | voltage resistance of a pressure | voltage resistant request | requirement part can be improved reliably.

[Means of claim 2 ]
According to the means of claim 2 , the press-fitting jig is composed of a direct body that is in direct pressure contact with the metal body and an indirect body that is in direct pressure contact with the metal body without being directly in pressure contact with the metal body.
As a result, the body can be directly attached to the metal body, and the indirect body can be pressed into the direct body attached to the metal body, or the indirect body can be pulled out from the direct body. For this reason, the press-fitting and pull-out of the press-fitting jig can be performed without damaging the metal body.

[Means of claim 3 ]
According to the third aspect , the surface of the press-fitting jig has an exposed surface exposed to at least one of the first space and the second space in a state of being press-fitted into the metal body.
Thereby, the expansion | swelling which arises in a press-fitting jig with heat processing can be escaped by an exposed surface. For this reason, it is possible to prevent an excessive stress from being generated in the metal body due to the expansion of the press-fitting jig during the heat treatment.

[Means of claim 4 ]
According to the means of claim 4 , the press-fitting jig has a hollow.
Thereby, the expansion | swelling which arises in a press-fit jig | tool with heat processing can be escaped equally on the surface which forms a hollow. For this reason, it can prevent more reliably that an excessive stress generate | occur | produces in a metal body by expansion | swelling of a press-fit jig | tool.

[Means of claim 5 ]
According to the means of claim 5 , the press-fitting jig is made of metal.
Since the amount of expansion of metal is large, using a press-fitting jig made of metal makes it possible to sufficiently expand the press-contact surface without excessive heat treatment or excessive press-fitting allowance. In addition to being able to be pulled, the metal structure can be sufficiently wound around the non-pressure contact surface portion to be in a compressed state. For this reason, sufficient compressive residual stress can be imparted to the non-press-contact surface portion without excessive heat treatment or excessive press-fitting allowance.

[Means of claim 6 ]
According to the means of claim 6 , the press-fitting jig is made of ceramic.
Since the amount of expansion due to heating is small, it is possible to prevent excessive stress from being generated in the metal body due to expansion of the press-fitting jig during heat treatment by using a press-fitting jig made of ceramic. .
Further, since the material of the metal body is different from the material of the press-fitting jig, the press-fitting jig slides with respect to the metal body, so that the press-fitting and drawing of the press-fitting jig can be performed more easily.

[Means of Claim 7 ]
According to the means of claim 7 , the metal body is manufactured by the manufacturing method according to any one of claims 1 to 6 .
This means indicates that the metal body is manufactured by the manufacturing method according to any one of claims 1 to 6 .

[Means of Claim 8 ]
According to the means of claim 8 , the fuel supply pump is provided with the metal body according to claim 7 as one of the parts, and supplies fuel to the internal combustion engine. The metal body forms a pressurizing chamber into which fuel to be supplied to the internal combustion engine flows in and flows in, or flows out after being pressurized.
As a result, a metal body having sufficient pressure resistance against repeated intake of fuel into the pressurization chamber and discharge of fuel from the pressurization chamber can be used as a component of the fuel supply pump.

It is sectional drawing in alignment with the shaft of a fuel supply pump, and a block diagram of a fuel-injection apparatus (Example 1). It is sectional drawing perpendicular | vertical to the shaft of a fuel supply pump (Example 1). (A) is sectional drawing which shows a press-fit process, (b) is sectional drawing which shows a heat treatment process, (c) is sectional drawing which shows extraction of a press-fit jig | tool (Example 1). (A) is explanatory drawing which shows the opening edge of 2nd space with respect to 1st space, (b) is explanatory drawing which shows the tension | pulling direction by the fuel pressure of the 1st space in one end and the other end vicinity part, (c ) Is an explanatory view showing the pulling direction by the fuel pressure in the second space in the vicinity of one end and the other end (Example 1). (A) is sectional drawing which shows a press injection process, (b) is AA sectional drawing of (a) (Example 2). It is sectional drawing which shows a press injection process (Example 3). (A) is sectional drawing which shows a press-fit process, (b) is BB sectional drawing of (a), (c) is a front view of a press-fitting jig (Example 4). It is sectional drawing in alignment with the shaft of a fuel supply pump, and a block diagram of a fuel-injection apparatus (conventional example).

The metal body according to the first embodiment includes a cylindrical first space and a cylindrical second space that opens in a side wall surface of the first space and connects to the first space, and the second body has a second space with respect to the first space. The opening edge is convex.
In addition, the metal body manufacturing method of the first embodiment includes a pressure applying step for increasing the pressure resistance of the opening edge, and the pressure applying step includes a press-fitting jig having rigidity equal to or higher than the rigidity of the metal body in the first space. And a press-fitting process for press-fitting into at least one of the second spaces, a heat-treating process for heat-treating the metal body in a state where the press-fitting jig is press-fitted, and a drawing process for pulling out the press-fitting jig from the metal body after the heat treatment process. Have.

In the heat treatment process, carburization is performed simultaneously.
In addition, the opening edge has a pressure-resistant requirement part that needs to improve the pressure resistance against repeated flow of fluid into and out of the first space and the second space. Even in this state, it is exposed to the first space and the second space.
The surface of the press-fitting jig has an exposed surface exposed to at least one of the first space and the second space while being press-fitted into the metal body.
Furthermore, the press-fitting jig is made of metal.

  The fuel supply pump according to the first embodiment is provided with a metal body as one of the parts, and supplies fuel to the internal combustion engine. The metal body forms a pressurizing chamber into which fuel to be supplied to the internal combustion engine flows in and flows in, or flows out after being pressurized.

According to the metal body manufacturing method of the second embodiment, the press-fitting jig is composed of a direct body that is in direct contact with the metal body and an indirect body that is in direct contact with the body without being in direct contact with the metal body.
According to the metal body manufacturing method of the third embodiment, the press-fitting jig has a hollow.
According to the metal body manufacturing method of the fourth embodiment, the press-fitting jig is made of ceramic.

[Configuration of Example 1]
The structure of the metal body 1 manufactured by the manufacturing method of Example 1 is demonstrated using FIG. 1 and FIG.
The metal body 1 is, for example, one component of a fuel supply pump 3 that supplies high-pressure fuel to an internal combustion engine (not shown) via a pressure accumulating container such as a common rail 2 and slidably supports the plunger 4. The fuel supply pump 3 constitutes a high-pressure pump 6 that pressurizes and discharges the fuel in the pressurization chamber 5.

  The fuel supply pump 3 constitutes a part of a pressure accumulation type fuel injection device 8 that injects fuel accumulated in a high pressure state by the common rail 2 to an internal combustion engine (not shown) by an injector 7. The fuel is pumped up from the fuel and supplied to the common rail 2 by being pressurized and discharged. The fuel injection device 8 includes an electronic control unit (not shown: hereinafter referred to as ECU) that controls the operation of each device.

The metal body 1 includes a cylindrical first space 13, and a cylindrical second space 14 that opens to a side wall surface of the first space 13 and connects to the first space 13. The opening edge 15 of the space 14 is convex.
The plunger 4 is supported and accommodated in the first space 13 so as to be slidable in the axial direction, and the axis of the first space 13 and the axis of the plunger 4 substantially coincide with each other. A part of the first space 13 is partitioned liquid-tightly by the plunger 4 to form the pressurizing chamber 5.

  Here, the plunger 4 is supported by the metal body 1 such that one end in the axial direction protrudes from the first space 13 toward one end, and a plunger having a diameter larger than that of the plunger 4 is provided at one end of the protruding plunger 4. A head 17 is provided and integrated with the plunger 4. The plunger 4 is driven by a cam mechanism 18 disposed on one end side of the first space 13 and reciprocates in the axial direction while defining one end of the pressurizing chamber 5 by the other end portion of the plunger 4. The volume of the pressurizing chamber 5 is varied by the reciprocating motion. Note that the other end of the pressurizing chamber 5 (that is, the other end of the first space 13) is partitioned by a suction valve 19 that intermittently sucks fuel into the pressurizing chamber 5.

  In addition, the first space 13 is expanded in diameter so that the range near the other end of the movement range of the plunger 4 in the axial direction does not receive the sliding contact of the plunger 4. The second space 14 is connected to this range.

  Here, the cam mechanism 18 is rotationally driven by the internal combustion engine, the cam 21 is eccentrically integrated with the shaft 21, and is driven to revolve around the axis of the shaft 21 by the rotation of the shaft 21. The cam 22 has a well-known configuration that has a cam 22 bearing on the inner peripheral side and a cam ring 23 that is driven to revolve without changing its posture by revolving the cam 22.

  The plunger head 17 is urged in the axial direction by the spring 24 to always contact the contact surface 25 of the cam ring 23, and relatively moves on the contact surface 25 in the third direction according to the revolution of the cam ring 23. While reciprocating, it reciprocates in the axial direction of the first space 13 (note that the third direction is a direction perpendicular to both the axial direction of the first space 13 and the axial direction of the shaft 21). Accordingly, the plunger 4 can reciprocate in the axial direction of the first space 13 to change the volume of the pressurizing chamber 5.

  A low-pressure feed pump 27 that pumps fuel from the fuel tank 9 is provided at one axial end of the shaft 21, and the low-pressure feed pump 27 is directly driven to rotate by the shaft 21. Then, the fuel pumped up by the low pressure feed pump 27 is metered by a metering valve (not shown) electronically controlled by the ECU, and then flows toward the high pressure pump 6 and is sucked into the pressurizing chamber 5. .

  In the second space 14, a check valve 30 including a valve body 28 and a spring 29 is accommodated, and a connection member 31 is screwed to connect a pipe (not shown) leading to the common rail 2. The check valve 30 is opened when the volume of the pressurizing chamber 5 is reduced and the fuel pressure in the pressurizing chamber 5 is increased to a predetermined valve opening pressure or more, and fuel is supplied from the pressurizing chamber 5. It is provided to let it flow out.

  With the above configuration, in the fuel supply pump 3, the pressurizing chamber 5 is expanded when the pressurizing chamber 5 is expanded and the fuel pressure in the pressurizing chamber 5 is reduced by the movement of the plunger 4 toward one end in the axial direction. The fuel is sucked into and flows in. When the plunger 4 moves toward the other end in the axial direction, the pressurizing chamber 5 is contracted and the fuel pressure in the pressurizing chamber 5 is increased to exceed the valve opening pressure of the check valve 30. Fuel is discharged from the chamber 5 and flows out into the common rail 2.

As described above, according to the fuel supply pump 3, since the increase and decrease of the fuel pressure are repeated in the pressurizing chamber 5, the stress load is repeatedly concentrated on the convex opening edge 15.
Therefore, the opening edge 15 of the metal body 1 is used as a component of the fuel supply pump 3 with improved pressure resistance.

[Production Method of Example 1]
A method for manufacturing the metal body 1 according to the first embodiment will be described with reference to FIGS.
First, the method of manufacturing the metal body 1 includes a pressure applying step for increasing the pressure resistance of the opening edge 15, and the pressure applying step includes the press-fitting jig 33 having a rigidity equal to or higher than the rigidity of the metal body 1 in the first space 13. A press-in process for press-fitting into the metal body, a heat-treating process for heat-treating the metal body 1 in a state where the press-fitting jig 33 is press-fitted, and a drawing-out process for pulling out the press-fitting jig 33 from the metal body 1 after the heat treatment process.

In the press-fitting process, the press-fitting jig 33 is press-fitted into a portion of the first space 13 whose diameter is enlarged near the other end to which the second space 14 is connected.
Here, the press-fitting jig 33 is provided in a substantially cylindrical shape using a metal as a raw material, and a part of the outer peripheral portion of the press-fitting jig 33 is chamfered so as to be parallel to the axial direction during press-fitting to form a flat surface 34. ing. Further, the cylindrical outer peripheral surface excluding the flat surface 34 forms a pressure contact surface 35 that is in pressure contact with the metal body 1. The press-fitting jig 33 is press-fitted into the first space 13 so that the flat surface 34 faces the opening edge 15 in the radial direction, and the periphery of the opening edge 15 in the first space 13 is occupied by the press-fitting jig 33. It remains as space without being done.

Of the side wall surfaces forming the first and second spaces 13, 14, the portion that receives the pressure contact surface 35 is referred to as a pressure contact surface portion 36, and the portion that does not receive the pressure contact surface 35 is referred to as a non-pressure contact surface portion 37. If so, the opening edge 15 is included in the non-pressure contact surface portion 37.
For this reason, the opening edge 15 is exposed to the first space 13 and the second space 14 even if the press-fitting jig 33 is press-fitted into the metal body 1. Further, the flat surface 34 becomes an exposed surface 38 exposed to the first space 13 in a state where the press-fitting jig 33 is press-fitted into the metal body 1.

Of the entire circumference of the opening edge 15, the portion where the stress is generated is near one end in the axial direction and near the other end in the axial direction (hereinafter referred to as one end and other end vicinity portions 41 and 42, respectively).
That is, when the plunger 4 moves to the other end side in the axial direction and the fuel pressure in the pressurizing chamber 5 is increased, both side wall surfaces forming the first and second spaces 13 and 14 have increased fuel pressure. It is expanded and pulled by.

  Thereby, in the one end and the other end vicinity portions 41 and 42, the pulling directions due to the fuel pressure in the first and second spaces 13 and 14 substantially coincide with each other, and the fuel pressures in the first and second spaces 13 and 14 depend on each other. Tensile stresses are added together without canceling each other. For this reason, one end and the other end vicinity portions 41 and 42 in the entire circumference of the opening edge 15 are portions where stress is generated greatly.

  Therefore, if a portion of the opening edge 15 that needs to have a particularly high pressure resistance against repeated increase / decrease of the fuel pressure in the pressurizing chamber 5 is called a pressure resistance requesting portion, the pressure resistance requesting portion has one end and the vicinity of the other end Parts 41 and 42. Therefore, the press-fitting jig 33 reliably increases the pressure resistance in the pressure-requiring part, so that the one end and the other end vicinity parts 41 and 42 that are the pressure-requiring parts are first and second even when pressed into the metal body 1. The flat surface 34 is chamfered so as to be exposed to both the spaces 13 and 14 and to be included in the non-pressure contact surface portion 37.

In the heat treatment step, carburization is performed simultaneously with the heat treatment.
Then, after the heat treatment step, the press-fitting jig 33 is pulled out from the first space 13 in the pulling step. In the press-fitting jig 33, the connection portion 43 where the flat surface 34 and the press-contact surface 35 intersect is R-attached, and when the press-fitting jig 33 is pulled out, damage to the side wall surface by the connection portion 43 is alleviated. .

[Effect of Example 1]
The metal body 1 according to the first embodiment includes a cylindrical first space 13 and a cylindrical second space 14 that opens to a side wall surface of the first space 13 and connects to the first space 13. The opening edge 15 of the second space 14 with respect to 13 is convex.
In addition, the method for manufacturing the metal body 1 includes a pressure applying step for increasing the pressure resistance of the opening edge 15, and the pressure applying step includes a press-fitting jig 33 having a rigidity equal to or higher than the rigidity of the metal body 1 in the first space. 13 includes a press-fitting process for press-fitting into the metal body 13, a heat treatment process for heat-treating the metal body 1 in a state where the press-fitting jig 33 is press-fitted, and a drawing process for extracting the press-fitting jig 33 from the metal body 1 after the heat treatment process.

Thereby, the pressure | voltage resistance of the opening edge 15 can be improved.
Here, although the mechanism which can improve the pressure | voltage resistance of the opening edge 15 is not clear, it estimates as follows.

First, the press-contact surface portion 36 is expanded and pulled by press-fitting the press-fitting jig 33. Next, when the metal body 1 is heat-treated with the press-fitting jig 33 being press-fitted, the metal structure of the press-contact surface portion 36 wraps around the non-press-contact surface portion 37 including the opening edge 15 due to the change in the metal structure, and the non-press-contact surface portion 37 is compressed. It becomes a state. Then, by pulling out the press-fitting jig 33 from the metal body 1 after the heat treatment, the tension of the press-contact surface portion 36 is released and compressive residual stress is applied to the non-press-contact surface portion 37.
As described above, the pressure resistance of the opening edge 15 in the metal body 1 can be increased.

In the heat treatment process, carburization is performed simultaneously.
Thereby, the non-pressure contact surface part 37 is hardened also by the carburizing process. For this reason, the hardness of the opening edge 15 can be increased and the pressure resistance can be further increased.

Further, one end and the other end vicinity portions 41 and 42 of the opening edge 15 are pressure-resistant request portions, and are exposed to the first space 13 and the second space 14 even when the press-fitting jig 33 is press-fitted into the first space 13. doing.
Accordingly, the one end and the other end vicinity portions 41 and 42 which are pressure-resistant request portions can be surely included in the non-pressure contact surface portion 37, and thus the pressure resistance of the one end and the other end vicinity portions 41 and 42 as the pressure-proof request portions is ensured. Can be increased.

Further, the flat surface 34 becomes an exposed surface 38 exposed to the first space 13 even when the press-fitting jig 33 is press-fitted into the metal body 1.
Thereby, the expansion generated in the press-fitting jig 33 due to the heat treatment can be released on the flat surface 34. For this reason, it is possible to prevent an excessive stress from being generated in the metal body 1 due to the expansion of the press-fitting jig 33 during the heat treatment.

Further, the press-fitting jig 33 is made of metal.
Since the amount of metal expansion due to heating is large, the press-fit surface portion 36 can be formed by using the press-fitting jig 33 made of metal as a raw material without performing heat treatment excessively or providing the press-fitting jig 33 excessively. The metal structure can be sufficiently expanded and pulled, and the metal structure can be sufficiently wound around the non-pressure contact surface portion 37 to be in a compressed state. For this reason, sufficient compressive residual stress can be imparted to the non-press-contact surface portion 37 without excessively performing heat treatment or providing the press-fitting jig 33 excessively.

[Production Method of Example 2]
According to the manufacturing method of the metal body 1 of the second embodiment, the press-fitting jig 33 is directly connected to the metal body 1 and two identical direct bodies 45a and 45b that are in direct pressure contact with the metal body 1, as shown in FIG. It consists of one indirect body 46 that is in direct contact with the bodies 45a and 45b without being in pressure contact.

The direct bodies 45a and 45b each have four flat surfaces 47a to 47d parallel to the axial direction, the flat surfaces 47a and 47b are orthogonal, and the flat surfaces 47c and 47d are also orthogonal. Further, the flat surfaces 47b and 47c are provided so as to be included in the same plane. Between the flat surfaces 47a and 47d, there is provided a cylindrical pressure contact surface 35 that is pressed against the pressure contact surface portion 36, and between the flat surfaces 47c and 47d, a cylindrical surface that receives the pressure of the indirect body 46 is provided. A pressure contact surface 48 is provided.
The indirect body 46 is provided in a columnar shape, and a cylindrical outer peripheral surface forms a pressure contact surface 49 where the pressure contact surface 48 is in pressure contact.

  In the press-fitting step, for example, the direct bodies 45a and 45b are placed in the first space so that the flat surface 47a of one direct body 45a and the flat surface 47d of the other direct body 45b face the opening edge 15 in the radial direction. 13 is mounted on the metal body 1. At this time, the direct bodies 45a and 45b are mirrored across the axis of the first space 13, and accordingly, the flat surface 47b of the direct body 45a and the flat surface 47c of the direct body 45b face each other in parallel. The flat surface 47c of the direct body 45a and the flat surface 47b of the direct body 45b face each other in parallel. Further, the pressure contact surface 48 of the direct body 45a and the pressure contact surface 48 of the direct body 45b are mirrored so as to be included in the same cylindrical surface.

  Subsequently, the indirect body 46 is pressed into the direct bodies 45 a and 45 b arranged in the first space 13. Thus, the pressure contact surface 49 of the indirect body 46 is in direct contact with the pressure contact surfaces 48 of the bodies 45a and 45b, and the pressure contact surface 35 of the direct bodies 45a and 45b is in pressure contact with the pressure contact surface portion 36.

Thereafter, in the heat treatment step, heat treatment and carburizing treatment are performed while maintaining the pressure contact state of the indirect body 46 against the direct bodies 45a and 45b and the pressure body contact state of the direct bodies 45a and 45b against the metal body 1. At this time, the flat surfaces 47a to 47d are exposed surfaces 38 exposed in the first space 13, and the expansion generated in the direct bodies 45a and 45b and the indirect body 46 is released by the flat surfaces 47a to 47d.
Then, after the heat treatment step, the press-fit state is released by pulling out the indirect body 46 from the direct bodies 45 a and 45 b, and the press-fitting jig 33 is completely removed from the metal body 1.

[Effect of Example 2]
According to the manufacturing method of the metal body 1 of the second embodiment, the press-fitting jig 33 includes two identical direct bodies 45a and 45b that are directly pressed against the metal body 1, and a direct body 45a that is not directly pressed against the metal body 1. , 45b and one indirect body 46 that is in pressure contact.
Accordingly, the bodies 45a and 45b are directly attached to the metal body 1, and the indirect body 46 is press-fitted into the direct bodies 45a and 45b attached to the metal body 1, or the indirect body 46 is moved from the direct bodies 45a and 45b. It can be pulled out. For this reason, the press-fitting jig 33 can be pressed and pulled out without damaging the metal body 1.

Example 3
According to the method for manufacturing the metal body 1 of the third embodiment, the press-fitting jig 33 has two flat surfaces 51a and 51b that are parallel to each other and parallel to the axial direction when press-fitted, as shown in FIG. And a cylindrical surface 52a that forms a cylindrical hollow 52 that is coaxial with the first space 13 when press-fitted. For example, the press-fitting jig 33 is press-fitted into the metal body 1 so that the flat surface 51a faces the opening edge 15 in the radial direction.

Further, the flat surfaces 51a and 51b and the cylindrical surface 52a are exposed surfaces 38 exposed in the first space 13, and the expansion occurring in the press-fitting jig 33 in the heat treatment step is the flat surfaces 51a and 51b and the cylindrical surface 52a. Missed out.
The pressure contact surface 35 with respect to the pressure contact surface portion 36 is between the one circumferential end of the flat surface 51a and the other circumferential end of the flat surface 51b, and around the other circumferential end of the flat surface 51a and the flat surface 51b. It is provided between the direction one end side.

  Thereby, in the cylindrical surface 52a, the expansion | swelling which arises in the press-fit jig | tool 33 with heat processing can be escaped equally. For this reason, it can prevent more reliably that an excessive stress generate | occur | produces in the metal body 1 by expansion | swelling of the press-fit jig | tool 33. FIG.

Example 4
According to the method for manufacturing the metal body 1 of the fourth embodiment, in the press-fitting process, the press-fitting jig 33 is press-fitted into the second space 14 as shown in FIG.
Here, the press-fitting jig 33 is provided by chamfering the cylindrical body at two locations on the outer peripheral portion. Then, two flat surfaces 54a and 54b that are parallel to each other and parallel to the axial direction of the second space 14 are provided by chamfering the outer peripheral portion. The cylindrical outer peripheral surface excluding the flat surfaces 54 a and 54 b forms a pressure contact surface 35 with respect to the metal body 1.

  For example, the press-fitting jig 33 is press-fitted into the second space 14 such that the flat surfaces 54 a and 54 b face one end and the other end vicinity portions 41 and 42 in the radial direction of the second space 14, respectively. Thereby, the one end and the other end vicinity portions 41 and 42 are included in the non-pressure contact surface portion 37, and the pressure resistance is reliably improved through the heat treatment step. The flat surfaces 54a and 54b are mainly exposed surfaces 38 exposed in the second space 14, and expansion generated in the press-fitting jig 33 in the heat treatment step is released by the flat surfaces 54a and 54b.

Example 5
According to the method for manufacturing the metal body 1 of the fifth embodiment, the press-fitting jig 33 is made of ceramic.
Since the amount of expansion due to heating is small, the use of the press-fitting jig 33 made of ceramic as a raw material prevents excessive stress from being generated in the metal body 1 due to expansion of the press-fitting jig 33 during heat treatment. be able to.
Further, since the material of the metal body 1 and the material of the press-fitting jig 33 are different, the press-fitting jig 33 slides with respect to the metal body 1, so that the press-fitting and drawing of the press-fitting jig 33 can be performed more easily. .

[Modification]
The aspect of the pressure | voltage resistant provision process with respect to the metal body 1 is not limited to Examples 1-5, A various modification can be considered.
For example, in the pressure resistance application process of the first to fifth embodiments, the press-fitting jig 33 is press-fitted only into one of the first space 13 and the second space 14. The press-fitting jig 33 may be press-fitted into the space.

In addition, the press-fitting jig 33 of Example 2 was composed of two direct bodies 45a and 45b and one indirect body 46, but the number of direct bodies 45 and indirect bodies 46 is arbitrary, for example, The press-fitting jig 33 may be constituted by three direct bodies 45 and two indirect bodies 46.
In addition, the structure which divides the press-fit jig 33 into the direct body 45 and the indirect body 46, the structure which provides the hollow in the press-fit jig 33, and escapes expansion | swell of the press-fit jig 33 by the surface which forms a hollow, and a ceramic material The configuration of providing the press-fitting jig 33 can be used in appropriate combination.
Furthermore, although the apparatus in which the metal body 1 is incorporated as a component in the first to fifth embodiments is the fuel supply pump 3, the metal body 1 may be used as a component of the common rail 2 or the injector 7.

DESCRIPTION OF SYMBOLS 1 Metal body 3 Fuel supply pump 5 Pressurization chamber 13 1st space 14 2nd space 15 Open edge 33 Press-fit jig 34 Flat surface (exposed surface)
38 Exposed surface 41 Near one end (pressure-requiring part)
42 Near the other end (withstand pressure requirement)
45a, 45b Direct body 46 Indirect bodies 47a-47d Flat surface (exposed surface)
51a, 51b Flat surface (exposed surface)
52 Hollow 54a, 54b Flat surface (exposed surface)

Claims (8)

A cylindrical first space; and a cylindrical second space that opens to a side wall surface of the first space and connects to the first space, and an opening edge of the second space with respect to the first space is convex. In the manufacturing method of the metal body forming
The manufacturing method includes a pressure application step for increasing the pressure resistance of the opening edge,
This pressure application process is
A press-fitting step of press-fitting a press-fitting jig having a rigidity equal to or higher than the rigidity of the metal body into at least one of the first space and the second space;
A heat treatment step of performing a carburizing process at the same time as heat-treating the metal body in a state in which the press-fitting jig is press-fitted,
After this heat treatment step, it possesses a drawing process of withdrawing the stuffing jig from said metal body,
In the opening edge, there is a pressure-resistant request portion that needs to increase pressure resistance against repeated flow of fluid into and out of the first space and the second space,
The method of manufacturing a metal body, wherein the pressure resistance requesting part is exposed to the first space and the second space even when the press-fitting jig is press-fitted into the metal body. In the manufacturing method of the metal body of Claim 1,
The method of manufacturing a metal body, wherein the press-fitting jig includes a direct body that is in direct contact with the metal body and an indirect body that is in direct contact with the direct body without being directly in contact with the metal body. In the manufacturing method of the metal body of Claim 1 or Claim 2,
A method for producing a metal body, wherein the surface of the press-fitting jig has an exposed surface exposed to at least one of the first space and the second space in a state of being press-fitted into the metal body. . In the manufacturing method of the metal body of Claim 1 ,
The method for producing a metal body, wherein the press-fitting jig has a hollow . In the manufacturing method of the metal body as described in any one of Claim 1 thru | or 4,
A metal body manufacturing method, wherein the press-fitting jig is made of metal . In the manufacturing method of the metal body as described in any one of Claim 1 thru | or 4 ,
A metal body manufacturing method, wherein the press-fitting jig is made of ceramic . The metal body manufactured by the manufacturing method as described in any one of Claims 1 thru | or 6. A fuel supply pump provided with the metal body according to claim 7 as one of parts and supplying fuel to an internal combustion engine,
The fuel supply pump according to claim 1, wherein the metal body forms a pressurizing chamber in which fuel to be supplied to the internal combustion engine flows in and flows in, or pressurizes and flows out.

Images