JPH04102770U - Hole processing equipment - Google Patents

Abstract

(57) [Summary] [Purpose] The main feature of this invention is to improve fatigue strength by uniformly striking the inner peripheral surface of a hole formed in a member. [Structure] This in-hole machining device includes a nozzle 18 that is rotatably supported around its central axis within a hole to be machined and has a hollow portion 20 formed therein;
At least one ball storage groove 42 is formed in the tip of each ball storage groove 8 in a radial direction and is movable in the radial direction within each ball storage groove 42 and is prevented from falling off. A ball 44 is housed in a state in which the outer circumferential portion protrudes radially outward from the outer circumferential surface of the nozzle 18 and the inner circumferential portion is located within the hollow portion 22 of the nozzle 18.
A polygonal pyramid part 40c is integrally disposed in the hollow part 22 of the nozzle 18 so as to be movable along the central axis of the nozzle 18 and relatively rotatable around the central axis, and the polygonal pyramid part 40c engages with the ball 44 at the tip. The rod 40 formed in
A biasing mechanism 4 whose polygonal pyramidal portion 40c engages with the ball 44 and biases the ball to move radially outward.
It is characterized by having 6.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea is a hole machining device for improving the fatigue strength of holes formed in parts. Regarding.

0002

[Conventional technology]

Traditionally, for example, steel crankshafts are subject to large loads that change periodically. In order to improve the fatigue strength of the crankshaft, induction hardening is used to Compressive residual stress is reduced by converting the surface metal structure to martensite and causing volume expansion. There are many ways to obtain power.

0003

[Problem that the idea aims to solve]

However, in the case of the above-mentioned steel crankshaft, the radial direction of this There are many holes for lubricating oil supply along the line, and with the increase in engine output in recent years, However, simply improving the fatigue strength of only the outer surface of the pin or journal will not improve the overall fatigue strength. It was not possible to increase the fatigue strength to the desired value, and it was difficult to increase the engine output. It is becoming difficult to do so. In particular, the compressive residual stress caused by the induction hardening mentioned above The method of obtaining Improving strength is difficult.

0004 Here, if an annular groove is formed on the outer periphery of the member, that is, the groove faces outward. For example, in the case where it is formed in an open state, As shown in Publication No. 3, after cutting and forming an annular groove, a circular die is inserted into the annular groove. By engaging the protrusions and rolling them under pressure, the surface roughness of the annular groove is improved and In addition, there is a known technique for increasing the hardness and uniformizing the machining accuracy. death However, such conventional technology is not suitable when an annular groove is formed on the outer periphery of the member. However, as mentioned above, it is possible to Due to its structure, it is impossible to apply it to the inner circumferential surface of a hole that extends out. There is a need for technological improvements that will reliably increase labor intensity.

[0005] This idea was created in view of the above-mentioned problems, and the purpose of this idea was to In-hole processing that can generate compressive residual stress on the surface and improve the fatigue strength inside the hole. The aim is to provide engineering equipment.

[0006]

[Means to solve the problem]

In order to achieve the above-mentioned purpose, the in-hole machining device related to this invention It is inserted into a hole, and rotates freely around its central axis within this hole. The nozzle is supported by a hollow section inside the nozzle, and the tip of this nozzle has a radius. At least one ball storage groove formed in a penetrating state along the direction, and each ball Stored in the storage groove so that it can move along the radial direction and is prevented from falling off. The outer circumferential part protrudes radially outward from the outer circumferential surface of the nozzle, and the inner circumferential part protrudes outward from the outer circumferential surface of the nozzle. a ball adapted to be located within the hollow portion of the nozzle; disposed so as to be movable along the central axis and relatively rotatable around the central axis. and a rod having an integrally formed polygonal pyramidal portion at its tip that engages with the ball; The polygonal pyramidal part of the rod engages the ball and pushes the ball radially outward. and a biasing mechanism that biases the nozzle to move, and by rotationally driving the nozzle. The inner peripheral surface of the hole is continuously hit by the ball to strengthen the inner peripheral surface of the hole. It is characterized by improving the degree of

[0007]

[Effect]

As mentioned above, by configuring the means to solve the problem, the nozzle can be rotated. By moving, the ball moves (revolutions) along the inner peripheral surface of the hole in the circumferential direction and , is deflected radially outward each time it crosses the ridgeline of the polygonal pyramid, continuously covering the inner circumferential surface of the hole. This creates compressive residual stress over the entire inner circumferential surface of the hole, reducing fatigue on the inner circumferential surface of the hole. This will allow you to improve your labor strength.

[0008]

【Example】 The configuration of one embodiment of the hole machining device according to this invention is shown below with reference to FIGS. 1 to 6. Refer to the following for a detailed explanation. A hole machining device 10 of this embodiment configured as shown in FIG. 1 is shown in FIG. As shown, a large number of holes are formed along the radial direction of the steel crankshaft CS. Compressive residual stress is generated on the inner peripheral surface of the lubricating oil supply hole HL, and the inner peripheral surface of this hole HL is It is designed to be used to improve the fatigue strength of

[0009] That is, as shown in FIG. 1, this hole machining device 10 has one end (left end in the figure) open. The other end (right end in the figure) of this holder 12 is not shown. It can be attached to a rotary drive mechanism such as a drilling machine via a chuck mechanism. It is structured like this. That is, inside this holder 12, there is an opening at the left end in the figure. A hollow portion 14 having a circular cross section is formed. Moreover, in the middle of this holder 12, A pin mounting hole 16 extending along the radial direction is formed through the center. It is. In the hollow part 14 of this holder 12, a nozzle member 18 is inserted from the left side in the figure. It has been inserted.

0010 This nozzle member 18 is inserted into the holder 12 and rotated integrally therewith. A thick cylindrical nozzle base 18a and a coaxial tube at the tip of the nozzle base 18a. A thin cylindrical nozzle body 18b that is integrally formed and inserted into the above-mentioned hole HL. It is composed of. Inside this nozzle base 18a, there is a section with an open right end in the figure. A circular hollow part 20 is formed in the nozzle body 18b, and a central axis thereof is formed in the nozzle body 18b. It extends along the line and is open at both left and right ends, especially at the right end. A rod insertion hole 22 communicating with the cavity 20 and having a circular cross section into which a rod described later is inserted. is formed. Here, as shown in FIG. 3, the nozzle member 18 is aligned with the holder 12. The part of the nozzle base 18a that is inserted into the hollow part 14 in order to rotate the body has an upper part. A pin insertion hole 24 is formed in alignment with the pin attachment hole 16 described above. With the pin 26 inserted through both the pin attachment hole 16 and the pin insertion hole 24, the pin 26 is removed. is attached.

[0011] Note that the diameter of the pin attachment hole 16 formed in the holder 12 is the same as the diameter of the pin 26. The pins 26 are set to be substantially the same, and the pins 26 inserted therein are tightly held. and , this pin 26 is integrally attached to the holder 12 via a set screw 28, as shown in FIG. is firmly fixed. On the other hand, a pin formed on the nozzle base 18a of the nozzle member 18 The pin insertion hole 24 is formed as a so-called stupid hole that is larger than the diameter of the pin 26. Ru. As a result, although the nozzle member 18 rotates integrally with the holder 12, the pin insertion hole With a margin (play) equal to the difference in diameter between pin 24 and pin 26, the direction of rotation is also , Also, in the axial direction, they are loosely connected.

0012 Here, in this embodiment, the axial direction between the holder 12 and the nozzle member 18 is A play absorption mechanism 30 is provided to elastically absorb play along the direction. This play absorption mechanism 30 is a cap that closes the right end of the hollow portion 20 of the nozzle member 18. a conical recess 34 formed on the right end surface of the cap member 32; , a press ball 36 that engages with this recess 34, and a press ball 36 that is moved to the left in the figure. It is composed of a biasing coil spring 38. In this way, the play absorption mechanism 30, the nozzle member 18 is always biased to the left with respect to the holder 12. Therefore, the play along the axial direction is elastically absorbed.

On the other hand, a rod member 40 is housed within the nozzle member 18 so as to be movable along the axial direction and rotatable relative to the nozzle member 18 . In detail, this rod member 40 is located in a hollow part 20 formed in the nozzle base part 18a of the nozzle member 18, and has a rod base part 40a that is slidable therein, and a distal end of this rod base part 40a. The rod body 40b is integrally formed coaxially with the nozzle body 18b, and is slidably inserted into the rod insertion hole 22 formed in the nozzle body 18b described above. As shown in FIG. 4, the tip of the rod body 40b is formed with a polygonal pyramid, specifically, in this embodiment, a regular hexagonal pyramid 40c. That is, this regular hexagonal pyramid portion 40c is composed of six substantially triangular planes PL ₁ to PL 6 , and the mutually adjacent planes PL ₁ ; PL ₂ , _{PL 2 ;} PL ₃ , PL ₃ ; PL ₄ , PL ₄ ; PL ₅ , PL ₅ ; PL ₆ , PL ₆ ; PL ₁ are partitioned by linear ridge lines RS ₁ to RS ₆ , respectively. Note that the tip of this rod body 40b terminates within the nozzle body 18b.

[0014] Also, the attachment of the nozzle body 18b where the above-mentioned rod body 40b terminates is also provided. Nearby, two ball storage grooves 42 extending along the radial direction and aligned with each other are provided. They are formed facing each other. That is, the outer end of each ball storage groove 42 is It opens on the outer peripheral surface of the rod body 40b, and the inner end communicates with the rod insertion hole 22. are doing. In addition, in each ball storage groove 42, a ball is placed in a state that cannot be dropped from each ball. A ball 44 is stored. That is, each hitting ball 44 is placed in a corresponding ball storage groove. 42, as shown in FIG. As shown in FIG. 6, the outer end of the rod body 40b is and a protruding position that protrudes outward. .

[0015] Furthermore, in this embodiment, a regular hexagon formed at the tip of the rod body 40b The conical part 40c is reliably engaged with the hitting ball 44, and the engagement with the hitting ball 44 is In order to press this against the inner circumferential surface of the hole HL with a predetermined pressure contact force, a rod is inserted. A biasing mechanism 46 is disposed within the base portion 40a. This biasing mechanism 46 is shown in FIG. As shown in FIG. A stopper member 48 having a portion 48a is provided, and the stopper member 48 and the between the rod member 40 and the rod member 40, from the stopper member 48 to the rod member 40. A first spacer 50 is disposed, and a plurality of spacers, four in this embodiment. A disc spring assembly 52 composed of a disc spring, a second spacer 54, It is configured to include several rolling rollers 56 and a third spacer 58. That is, in this biasing mechanism 46, the third spacer 58 directly engages the rod portion. It is in contact with the right side surface of the rod base 40a of the member 40.

[0016] Since the biasing mechanism 46 is configured in this way, the force is generated by the disc spring assembly 52. The generated urging force is transmitted to the rod member 40 via the plurality of rolling rollers 56. become. As a result, the rod member 40 is directed to the left in the figure by this biasing mechanism 46. The regular hexagonal pyramid portion 40c formed at the tip of the rod member 40 is biased by the impact roller. It comes into pressure contact with the rubber 44. Therefore, each striking roller 44 is directed radially outward. It will be biased with a predetermined biasing force.

[0017] As shown in FIG. 1, a rod is attached to the tip of the nozzle body 18b of the nozzle member 18. A closing member 60 is screwed into the insertion hole 22 in a state where the opening at its tip is closed. detail In the figure, the closing member 60 is formed on the inner circumferential surface of the tip of the rod insertion hole 22. From the right side of this male threaded portion 60a, , a stopper extending toward the tip (i.e., the apex) of the regular hexagonal pyramid portion 40c described above. It is integrally formed with the tube 60b. In this way, the closing member 60 is attached. The state in which the stopper rod 60b is in contact with the tip of the regular hexagonal pyramid part 40c is achieved by Thus, the maximum leftward deflection position of the rod member 40 is defined.

[0018] Further, as shown in FIG. 1, the inner peripheral surface of the holder 12 and the nozzle base 1 of the nozzle member 18 are A pair of elastic rings 62 are interposed between the outer circumferential surface of 8a. These elastic Due to the arrangement of the ring 62, the ring 62 exists between the above-mentioned pin 26 and the nozzle member 18. The state of misalignment between the center axis of the hole HL and the center axis of the holder 12 due to "play" This will ensure compliance in the current situation.

[0019] The machining operation in the hole machining device 10 configured as above will be explained. First, the hole machining device 10 of this embodiment is mounted on a drilling machine (not shown) with a chip (not shown). Attach via the jack mechanism. On the other hand, holes HL are formed to increase fatigue strength. The crankshaft CS is fixed to a fixing jig (not shown). And this hole Insert the nozzle body 18b of the nozzle member 18b of the hole processing device 10 into the HL. . By this insertion operation, the ball is stored in the ball storage groove 42 formed in the nozzle body 18b. The stored hitting balls 44 are in a state in which their respective outer parts are pressed against the inner circumferential surface of the hole HL. Become. Then, the center axis of the hole HL and the center axis of the in-hole processing device 10 are aligned with each other. In this state, drive the drilling machine to move the holder 12 of the hole machining device 10. Rotationally driven around the central axis of.

[0020] As a result, the holder 12 and the pin 26 are connected to rotate together. The slide member 18 rotates in synchronization with the rotation of the holder 12. obey In the ball storage groove 42 formed in the nozzle body 18b of this nozzle member 18, The accommodated hitting ball 44 rotates within the hole HL as the nozzle member 18 rotates ( (revolution) Further, each hitting ball 44 is rotated as the nozzle member 18 rotates. During the revolution, the ball automatically moves in the ball storage groove 42 due to rolling contact with the inner circumferential surface of the hole HL. The body will be rotated (rotated) around its central axis.

[0021] On the other hand, the rod member 40 that is in pressure contact with these hitting balls 44 has a biasing mechanism 4. While the urging force from the countersunk screw assembly 52 of No. 6 is acting, the inner periphery of the hole HL Directly receives the drag force from the hitting ball 44 that is in pressure contact with the surface, and substantially It is regulated so that it stays within. Here, the biasing force from the biasing mechanism 46 is Since it is transmitted to the rod member 40 via the ring 56, the nozzle member 18 and the rod Relative rotational movement between the member 40 and the member 40 is allowed through these rolling rollers 56. becomes. That is, the rod member 40 is in a stopped state, and the rod member 40 is moved around it. A situation occurs in which the nozzle member 18 rotates. In this way, the nozzle member 1 8, each striking roller 44 revolves around the regular hexagonal pyramid portion 40c. .

[0022] Here, as each striking roller 44 revolves around the regular hexagonal pyramid part 40c, as already explained, each striking roller 44 engages with any one of the planes PL ₁ to PL ₆ of the regular hexagonal pyramid part 40c. In this case, as shown in FIG. 5, each striking roller 44 is brought to its storage position with most of it stored in the ball storage groove 42. In a state where each striking roller 44 is brought to the storage position, each striking roller 44 does not substantially press against the inner circumferential surface of the hole HL.

[0023] However, for example, if the nozzle member 18 is rotated 30 degrees from the state shown in FIG. As shown in FIG. ₁ ~RS₆ It will climb to the top. As a result, each striking roller 44 is in the protruding position. As a result, each striking roller 44 presses the inner peripheral surface of the hole HL extremely strongly. Pressing with force, that is, hitting. Furthermore, as is clear from this explanation, the above The biasing force of the disc spring assembly 52 of the biasing mechanism 46 is due to this extremely strong contact force. In other words, it defines the impact force. Then, the hole H formed by each striking roller 44 The striking action on the inner circumferential surface of L is such that each striking roller 44 hits either one of the regular hexagonal pyramids 40c. ridgeline RS₁ ~RS₆ This is done each time the roller 44 rides on the If you pay attention to this, each rotation of the nozzle member 18 means that six impact operations are performed. .

[0024] In this way, in this embodiment, the holder 12 is rotationally driven. Therefore, the inner circumferential surface of the hole HL is sequentially struck along the circumferential direction by each striking roller 44, By repeating the rotation of the holder 12 several times, the inner peripheral surface of the hole HL is completely rotated. It will be attacked for a long time. In this way, the inner diameter of this hole HL is expanded, The area of the inner peripheral surface is expanded. As a result, compressive residual stress is generated on the inner peripheral surface of the hole HL. occurs, and therefore, the fatigue strength at the inner circumferential surface of the hole HL is improved. Furthermore , the holder 12 is moved along the axial direction via a drilling machine, and the nozzle member 18 is inserted into the hole. By gradually pushing it into the hole HL, the inner circumferential surface of the hole HL is completely covered, and its fatigue is reduced. This will allow you to improve your labor strength.

As described above, the rod member 40 is regulated so as to remain substantially in that position with respect to the rotation of the nozzle member 18, but the hitting ball 44 is regulated to each ridge line RS of the regular hexagonal pyramid portion 40c. ₁ to RS ₆ , a component force acts to rotate the rod member 40. As a result, the rod member 40 will rotate slightly relative to the nozzle member 18. Therefore, in one rotation of the holder 12, each hitting ball 44 hits the inner peripheral surface of the hole HL six times, but in the next rotation of the holder 12, each hitting ball 44 hits the inner peripheral surface of the hole HL six times. The inner peripheral surface of the hole HL is struck six times at a different striking position from the striking position of the striking ball 44 during one rotation of the holder 12. In this way, the hitting ball 44 hits the inner peripheral surface of the hole HL substantially evenly over the entire circumference, and as a result, compression remains uniformly on the inner peripheral surface. Stress is generated and fatigue strength can be improved under good conditions.

[0026] Furthermore, in the embodiment described above, the above-mentioned "play" and the elastic ring 62 are Due to the existence of Compliance will occur. Here, the hole HL mentioned above is beyond the gun drill. If the axis of the hole HL is bent when it is machined using a twist drill, for example, However, even in this case, the above-mentioned compliance The nozzle member 18 inserted into the hole HL is formed with its axis bent based on the Hitting the inner peripheral surface of the hole HL with the hitting ball 44 while accurately following the hole HL It becomes possible to execute the action.

[0027] This invention is not limited to the configuration of the above-mentioned embodiment, but the gist of this invention is It goes without saying that various modifications can be made without departing from the above. For example, in the embodiment described above, the polygonal pyramid formed at the tip of the rod However, this idea is limited to this configuration. Any polygonal pyramid, such as a regular pentagonal pyramid or a heptagonal pyramid, is acceptable. stomach.

[0028] Further, in the embodiment described above, the ball storage grooves 42 are aligned with each other. Although it was explained that two wires are formed, this invention is limited to this configuration. There should be at least one ball storage groove, and the number can be arbitrary. For example, , 3 or 4 is fine. If multiple ball storage grooves are formed, each ball The hitting ball 44 is stored in the storage groove.

[0029]

[Effect of the idea]

As detailed above, the in-hole machining device according to this invention is capable of It is inserted into the hole and supported rotatably around its central axis within this hole. A nozzle with a hollow part formed inside and a radial line along the tip of this nozzle. At least one ball storage groove formed with a penetrating shape, and each ball storage groove. stored in the groove so as to be movable along the radial direction and prevented from falling off; The outer circumferential portion protrudes radially outward from the outer circumferential surface of the nozzle, and the inner circumferential portion protrudes radially outward from the outer circumferential surface of the nozzle. a ball adapted to be located within the hollow portion, and a ball positioned within the hollow portion of said nozzle; The tip is movable along the axis and relatively rotatable around the central axis. a rod integrally formed with a polygonal pyramidal portion that engages with the ball; , whose polygonal pyramidal portion engages the ball and moves the ball radially outward. and a biasing mechanism that biases the nozzle so that the nozzle is rotated. The inner peripheral surface of the hole is continuously hit by the ball to improve the strength of the inner peripheral surface of the hole. It is characterized by causing

[0030] Therefore, according to this invention, compressive residual stress is generated on the inner peripheral surface of the hole, and the inside of the hole is reduced. A hole machining device capable of improving fatigue strength will be provided.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view showing the configuration of an embodiment of a hole machining device according to the invention.

FIG. 2 is a partially exploded front view showing the configuration of a crankshaft as an object to be machined by this in-hole machining device.

FIG. 3 is a side sectional view of the hole machining device shown in FIG. 1 taken along line A-A.

FIG. 4 is a perspective view showing the shape of a regular hexagonal pyramid formed at the tip of the rod member.

FIG. 5 shows the configuration of the tip of the hole machining device shown in FIG.
FIG. 2 is a side sectional view taken along the line -B and showing the hitting ball in the storage position.

FIG. 6 shows the configuration of the tip of the hole machining device shown in FIG.
FIG. 3 is a side sectional view taken along the line -B and showing the hitting ball in a protruding position.

[Explanation of symbols]

10 In-hole processing device, 12 holder, 14 Hollow part, 16 pin mounting hole, 18 nozzle member, 18a nozzle base; 18b nozzle body; 20 hollow part, 20a female thread part, 22 Rod insertion hole, 24 pin insertion hole, 26 pins, 28 Set screw, 30 play absorption mechanism, 32 Cap member, 34 recess, 36 Press ball, 38 coil spring, 40 rod member, 40a Rod base; 40b Rod body; 42 Ball storage groove, 44 Hitting ball, 46 biasing mechanism, 48 Stopper member, 48a Male thread part, 50 first spacer, 52 Flat head screw assembly, 54 second spacer, 56 rolling roller, 58 third spacer, 60 Closure member, 60a Male thread; 60b Stopper rod; 62 It is an elastic ring.

Claims (1)

[Scope of utility model registration request] Claim 1: A nozzle that is inserted into a hole to be machined, is rotatably supported in the hole around its central axis, and has a hollow portion formed inside, and a tip of the nozzle. At least one ball storage groove is formed in a penetrating state along the radial direction, and the ball is stored in each ball storage groove movably along the radial direction and prevented from falling off, and the outer peripheral portion a ball projecting radially outward from the outer circumferential surface of the nozzle and having an inner circumferential portion located within the hollow portion of the nozzle; and a ball movable within the hollow portion of the nozzle along its central axis; and a rod which is disposed so as to be relatively rotatable around a central axis and has a polygonal pyramidal part integrally formed at its tip that engages with the ball; and a biasing mechanism that biases the ball to move outward in a radial direction, and by rotating the nozzle, the inner circumferential surface of the hole is continuously struck by the ball. A hole machining device characterized in that the strength of the inner circumferential surface of the hole is improved.