JP7075539B2 - Assembling structure of rolling roller to piston rod - Google Patents

Description

Technology related to the structure of assembling a rolling roller to a piston rod that slides in a cylinder.

As shown in FIGS. 2 and 5 of Reference 1, the hydraulic actuator used in the parking device includes a piston integrated with a piston rod that slides in the cylinder in the axial direction, and the piston rod is provided with the piston rod. A long hole extending in the axial direction is provided across the long hole, and the rolling roller constituting the roller bearing is housed inside the long hole. The rolling rollers are supported by pins, which are rotating support shafts arranged so as to cross the elongated holes. Further, the movement of the piston rod in the axial direction is controlled by the lock shaft of the magnetic lock device provided on the side thereof, which moves forward and backward toward the elongated hole while engaging with the rolling roller.

In FIG. 5 of Cited Document 1, the pin supporting the rolling roller is press-fitted and fixed to one of the through holes provided in each of the pair of elongated hole forming walls. That is, from the viewpoint of saving the press-fitting and shortening the press-fitting time, the pin is press-fitted only into the through-hole on the opposite side of the pair of facing through-holes to which the pin is inserted. The larger the press-fitting allowance (contact area of the pin with the through hole) of the pin into the through hole on the tip side, the greater the fixing holding force to the through hole. It is press-fitted to a position where it is almost flush with each other.

WO2017 / 038208 No.

However, when the pin is press-fitted into the through hole, the inner peripheral surface of the through hole is plastically deformed in the traveling direction of the pin due to the shearing force acting between the outer peripheral edge of the pin tip and the inner peripheral surface of the through hole. As a result, the peripheral edge of the opening of the through hole that exposes the tip of the pin may rise, or the inner peripheral surface of the through hole may be scraped off, causing thread burrs on the peripheral edge of the opening of the through hole. In this way, when the pin is press-fitted into the through hole of the piston rod, the protrusion generated on the sliding surface of the piston rod due to the swelling and the thread burr formed on the peripheral edge of the opening of the through hole is formed with respect to the cylinder. Since there is a risk of hindering the sliding operation of the cylinder rod, there has been a problem of an increase in manufacturing cost due to an increase in work man-hours and work time for removing by cutting or grinding. In view of the above problems, the present invention has a rolling roller to the piston rod , which is performed at low cost without generating a protrusion on the sliding surface of the cylinder rod even if the pin is press-fitted into the through hole of the cylinder rod. It provides the assembly structure of.

A piston rod integrated with a piston that slides in the cylinder in the axial direction, a long hole provided in the piston rod that penetrates in a direction orthogonal to the piston rod, and a pair of long holes facing each other across the long hole. The first through hole and the second through hole extending in the direction orthogonal to the axis of the piston rod provided on the elongated hole forming wall, respectively, and the pin press-fitted and fixed to the second through hole rotate via the inscribed hole. A rolling roller that is freely supported is provided, and the inner diameter of the second through hole is formed to be smaller than the inner diameter of the first through hole and the inscribed circular diameter of the inscribed hole provided in the rolling roller. With the rolling roller arranged so that the first through hole to the inscribed hole are all aligned between the pair of elongated hole forming walls, the pin is inserted in the order of the first through hole and the inscribed hole, and further. The structure is such that the tip of the pin is press-fitted into the second through hole to assemble the rolling roller to the piston rod, and the tip of the press-fitted pin is exposed to the inner peripheral edge of the second through hole. Is provided with a tapered hole side surface portion, and the outer peripheral edge portion of the tip of the pin has a tapered shape or an arc shape including an arc portion at least in the contact portion with the inner peripheral surface of the second through hole. A pin side edge is provided.

(Action) When the pin is press-fitted into the second through hole, no thread burr is generated between the pin and the inner peripheral surface of the second through hole, and the inner peripheral surface of the second through hole of the piston rod is not generated. Even if a swelling occurs on the inner peripheral surface of the second through hole due to the shearing force acting between the pin and the pin, the swelling occurs on the side surface portion of the hole. The swelling generated in the hole side surface is stored between the hole side surface and the pin side surface, and does not protrude to the sliding surface of the piston rod.

Further, the pin is formed on the press-fitting portion formed adjacent to the base end portion of the pin side surface taking portion at a position corresponding to the press-fitting surface of the second through hole into which the pin is press -fitted, and on the outer periphery of the press-fitting portion. It is desirable that the annular groove provided is provided, and the elastic return portion formed on the press-fitting surface of the second through hole by passing through the press-fitting portion penetrates and engages with the annular groove.

(Action) The press-fitting surface of the second through hole of the piston rod is elastically deformed outward in the radial direction by the press-fitting portion of the pin, and after passing through the press-fitting portion, elastically returns inward in the radial direction toward the annular groove of the press-fitting portion. However, the elastic return portion engages with the opening edge of the annular groove of the pin.

Further, it is desirable that the elastic return portion is in close contact with at least a part of the inner peripheral surface of the annular groove.

(Action) When the pin is press-fitted into the second through hole of the piston rod, the elastic return portion of the inner peripheral surface of the second through hole is not only the opening edge of the annular groove of the pin but also due to the passage of the press-fit portion. , Closely engages with at least part of the inner peripheral surface.

Further, in the pin which is the support shaft of the rolling roller, a large diameter portion larger than the outer diameter of the tip portion of the pin is continuously formed on the base end side of the annular groove, and the large diameter portion is formed. It is desirable that the tip is formed at a position where the pin abuts on the peripheral edge of the base end of the second through hole when the pin is press-fitted into the second through hole.

(Action) When the pin is press-fitted into the second through hole of the piston rod, the large diameter portion continuously formed on the base end side of the annular groove of the pin is the peripheral edge of the base end of the second through hole of the piston rod. By abutting on the portion, the movement of the pin toward the tip end with respect to the second through hole of the piston rod is restricted.

According to the structure of assembling the rolling roller to the piston rod, even if the pin is press-fitted into the second through hole of the piston rod, the thread burr and swelling that adversely affect the sliding of the piston rod are caused by the sliding surface of the piston rod. Since it does not protrude to the piston rod, it is possible to assemble the pin that supports the rolling roller to the piston rod at low cost.

According to the structure of assembling the rolling roller to the piston rod, when the pin is press-fitted into the second through hole of the piston rod, the elastic return portion formed on a part of the press-fit surface of the second through hole is in the radial direction. It elastically returns to the pin side toward the inside and enters the annular groove while engaging with the opening edge of the annular groove on the pin side, thereby positioning the pin in an axially immovable state and pulling it out. Stop. In addition to the elastic return force inside the radial direction that the press-fitting part receives from the press-fitting surface excluding the elastic return part of the piston rod, the pin is wiped out and strengthened by the elastic return part on the piston rod side that engages with the opening edge of the annular groove. It is positioned and fixed to the inner peripheral surface of the second penetrating portion of the piston rod.

According to the structure of assembling the rolling roller to the piston rod, when the pin is press-fitted into the second through hole of the piston rod, the elastic return portion which is a part of the inner peripheral surface of the second through hole is on the pin side. By invading the annular groove while engaging with the opening edge of the annular groove , the pin is prevented from coming off, and the elastic return portion is in close contact with at least a part of the inner peripheral surface of the annular groove. By doing so, the swing of the pin with respect to the piston rod after being fixed to the second through hole is suppressed, and the pin is completely and firmly fixed to the inner peripheral surface of the second through hole of the piston rod.

According to the structure of assembling the rolling roller to the piston rod, the large diameter portion formed on the pin side abuts on the peripheral edge of the base end of the second through hole of the piston rod, so that the pin in the second through hole is pressed. It is positioned immovably toward the tip of the piston rod, and the pin is wiped out and firmly fixed to the inner peripheral surface of the second through hole of the piston rod.

The perspective view of the piston rod which concerns on 1st Embodiment which shows the assembly structure of the rolling roller to a piston rod. A side view of a piston rod placed horizontally according to the first embodiment showing an assembly structure of a rolling roller to a piston rod. FIG. 2 is a sectional view taken along line II of FIG. 2, showing an assembly structure of a rolling roller to a piston rod of the first embodiment. FIG. 3 is an enlarged partial cross-sectional view of FIG. 3 showing a pin side surface portion, a hole side surface extraction portion, and an annular groove of the pin. FIG. 4 is an enlarged partial cross-sectional view showing a modified example of the annular groove of the pin shown in FIG. FIG. 3 is an axial sectional view showing a second embodiment of a structure for assembling a rolling roller to a piston rod. FIG. 6 is an enlarged partial cross-sectional view of FIG. 6 showing a pin side surface portion, a hole side surface extraction portion, and an annular groove of the pin. FIG. 7 is an enlarged partial cross-sectional view showing a modified example of the chamfered portion on the pin side shown in FIG. 7.

A first embodiment relating to the structure for assembling the rolling roller to the piston rod will be described with reference to FIGS. 1 to 3.

The piston rod 1 shown in FIGS. 1 and 2 has a cylindrical shape, and a piston 2 having an outer diameter larger than that of the piston rod 1 is integrated with the base end portion 1a. The piston rod 1 and the piston 2 are housed in a cylinder (not shown) to form a hydraulic actuator (not shown) for switching the parking brake on and off. The piston rod 1 engages in a small cylinder of a cylinder (not shown) and the piston 2 engages a large cylinder of a cylinder (not shown), both of which are hydraulic and spring resistant to hydraulic pressure (not shown). ) Reciprocates in the axial direction due to the reaction force, and is used to switch the parking brake on and off.

The piston rod 1 shown in FIGS. 1 and 2 has a pair of wall portions (1c, 1c, which are provided at the tip thereof facing each other via a notch 1b in the axial direction (direction along the central axis L1 of the piston rod 1). It has 1d) and a pair of holes of the same size (1e, 1f) provided so as to face the pair of wall portions. Further, in the vicinity of the central portion of the piston rod 1, there are a long hole 3 penetrating in a direction orthogonal to the central axis L1 of the piston rod and a pair of long hole forming walls (4, 5) facing each other across the long hole 3. It is formed.

As shown in FIGS. 2 and 3 , the pair of elongated hole forming walls (4, 5) have first through holes penetrating in the direction orthogonal to the central axis L1 of the piston rod (direction along the straight line L2), respectively. 6 and the second through hole 7 are formed. The pair of first through holes 6 and second through holes 7 are formed as circular holes, respectively, and are formed at positions facing each other. The pair of elongated hole forming walls (4, 5) are both formed to have a wall thickness t1, and as shown in FIG. 4, the inner peripheral edge of the outer peripheral side opening 7a that opens to the outer peripheral surface 1 g side of the piston rod 1. A tapered hole side surface portion 7b is formed in the portion, and the inner peripheral surface of the second through hole 7 excluding the hole side surface extraction portion 7b is a press-fitting surface 7c into which the pin 8 is press-fitted.

Since the second through hole 7 shown in FIGS. 2 and 3 press-fits the tip of the pin 8, the inner diameter D2 is smaller than the outer diameter d1 of the pin 8 so as to be tightly fitted to the pin 8. Is formed only small. The first through hole 6 and the inscribed hole 9 of the rolling roller 10 (the hole for inserting the pin 8 while inscribed in each of the plurality of cylindrical rolling elements 10a) need only be able to insert the pin 8. The inner diameter D1 of the first through hole 6 and the inscribed circle diameter D3 of the inscribed hole 9 (connecting the inner contacts of each rolling element 10a and the pin 8 so as to be an intermediate fit or a gap fit with respect to the pin). The diameter of the inscribed circle) is made larger than the inner diameter D2 of the second through hole 7, and is formed to be the same as or slightly larger than the outer diameter d1 of the pin 8. A rolling roller 10 is rotatably supported in the elongated hole 3 via a pin 8 arranged and fixed in the first through hole 6 and the second through hole 7 by means described later. The rolling roller 10 may be a rolling bearing and may have an inner ring like the rolling roller 34 of the second embodiment described later. The inscribed holes 9 of the rolling roller 10 with which the pins 8 are engaged are aligned and arranged inside the elongated holes 3 so as to have the same central axis L2 as the first through holes 6 and the second through holes 7.

As shown in FIGS. 1 and 2, the piston 2 is formed in a bottomed cylindrical shape, has a cylindrical pedestal portion 2a in the center, and slides inside a large cylinder of a cylinder (not shown) on the outer circumference of the tip. It has a moving flange portion 2b. Further, the piston 2 is integrated so as to be coaxial with the piston rod 1 (center axis L1) by joining the pedestal portion 2a to the base end portion 1a of the piston rod 1. The outer peripheral surface 1g of the piston rod 1 slides in a small cylinder of a cylinder (not shown), and the flange portion 2b slides in a large cylinder of a cylinder (not shown). The piston rod 1 and the piston 2 swing in the direction of the central axis L1 by inserting a stationary pin or the like (not shown) into the gap 3a between the elongated hole 3 and the rolling roller 10 in a direction orthogonal to the central axis L1. It is held immobile.

As shown in FIGS. 3 and 4, the pin 8 has a tapered pin side surface portion 11 on the outer peripheral edge portion of the tip portion 8a. It is desirable that the tapered pin side surface portion 11 is formed so as to have an inclination of more than 20 ° and an inclination of 30 ° or less with respect to the direction along the central axis L2 of the pin 8, and further, more than 0 °. And it is more desirable that it is formed so as to have an inclination of 20 ° or less. When the inclination of the pin side surface taking portion 11 is more than 20 ° and 30 ° or less, the base end portion 11a of the pin side surface taking portion 11 has the hole side surface taking portion 7b and the pin side surface with respect to the press-fitting surface 7c of the second through hole 7. When only a very small amount of thread burr that can be stored inside the taking portion 11 is formed and the inclination of the pin side taking portion 11 is more than 0 ° and 20 ° or less, the base end portion 11a of the pin side taking portion 11 is the second. Thread burrs are no longer formed on the press-fitting surface 7c of the through hole 7.

Further, as shown in FIG. 4, a press-fitting portion 12 is formed adjacent to the base end portion 11a of the pin side surface taking portion 11, and further, the press-fitting portion 12 has an outer circumference centered on the central axis L2 of the pin 8. A concave annular groove 13 orbiting the surface is formed. The annular groove 13 is formed at a position corresponding to the press-fitting surface 7c of the second through hole 7 of the slotted hole forming wall 5 into which the pin 8 is press-fitted. Specifically, assuming that the axial length of the pin side surface taking portion 11 is h1 with respect to the thickness t1 of the slotted hole forming wall 5, the press-fitting portion 12 is formed on the pin side surface taking portion 11 along the central axis L2. It is formed in the range from the base end portion 11a to the position 12a separated from the base end portion by t1-h1 (hereinafter referred to as the base end portion 12a of the press-fitting portion 12), and the annular groove 13 is formed on the pin side surface taking portion 11. It is formed within the range from the base end portion 11a to the base end portion 12a of the press-fitting portion, and faces the press-fitting surface 7c in the entire area thereof.

Here, the assembly of the rolling roller 10 to the piston rod 1 by the pin 8 will be described with reference to FIGS. 3 and 4. In FIG. 4 and FIG. 5 described later, the description of the rolling roller 10 is omitted for convenience of explanation. First, while aligning the inscribed holes 9 of the rolling roller 10 with the first through holes 6 and the second through holes 7 of the pair of elongated hole forming walls (4, 5), the rolling rollers 10 are aligned with the elongated holes 3. It is placed between the elongated hole forming walls (4, 5). Next, the tip portion 8a of the pin 8 is inserted in order from the first through hole 6 of the elongated hole forming wall 4 into the inscribed hole of the rolling roller 10, and finally inserted into the second through hole 7 of the elongated hole forming wall 5. Let me. Since the inner diameter D2 of the second through hole 7 is slightly smaller in length than the outer diameter d1 of the pin 8 and is formed so as to be tightly fitted, the tip portion 8a of the pin 8 has an outer peripheral side opening 7a. The press-fitting portion 12 is press-fitted into the press-fitting surface 7c of the second through hole 7 so as to be flush with each other.

As shown in FIG. 4, when the press-fitting portion 12 of the pin 8 is press-fitted into the second through hole 7, the second through-hole 7 press-fits the inner peripheral wall on the tip side of the base end portion 11a of the pin side surface taking portion 11. By being pressed in the tip direction by 12, a bulge is generated in the vicinity of the base end portion of the hole side surface taking portion 7b, or a part of the press-fitting surface 7c is scraped by the base end portion 11a of the pin side surface taking portion 11. , A small amount of thread burr that can be accommodated in the accommodating area 14 formed between the hole side surface removing portion 7b and the pin side surface removing portion 11 is generated. The swelling generated in the hole side surface 7b and the small amount of thread burrs generated from the press-fitting surface 7c are both formed inside the second through hole 7 between the hole side surface 7b and the pin side surface. Since it is housed in the housing area 14, it does not protrude to the outer peripheral surface 1g of the piston rod 1 and hinder the sliding of the piston rod 1.

On the other hand, as shown in FIGS. 3 and 4, the press-fitting surface 7c, which is the inner peripheral wall of the second through hole 7, has a pin press-fitting portion 12 having a portion on the proximal end side of the pin side surface taking portion 11 with respect to the proximal end portion 11a. The pin 8 is elastically deformed outward in the radial direction, and a part of the press-fitting surface 7c is formed in the annular groove after passing through the tip-side press-fitting portion (the portion between the base end portion 11a and the tip portion 13a of the annular groove 13). It elastically returns inward in the radial direction toward 13. The elastic return portion 15 formed by returning toward the annular groove 13 is engaged with the opening edge portion of the annular groove 13 of the pin 8, that is, the tip portion 13a and the base end portion 13b, and the annular groove 13 is engaged. Invade the inside of. In the pin 8, in addition to the press-fitting portion 12 being press-fitted and fixed to the press-fitting surface 7c of the second through hole 7, the elastic return portion 15 of the elongated hole forming wall 5 that has penetrated into the annular groove 13 is further fitted with the tip portion 13a. By engaging with the base end portion 13b in a pressed state, it is prevented from coming off in the direction along the central axis L2, so that it is more firmly fixed to the second through hole 7 of the elongated hole forming wall 5.

The axial length of the annular groove 13 (the length in the direction along the central axis L2) is formed to be shorter than that of t1-h1, and the tip portion 13a and the base end portion 13b of the annular groove 13 are formed. It is desirable that the pin side surface portion 11 is formed so as not to be adjacent to the base end portion 11 and the base end portion 12a of the press-fitting portion 12. In that case, the press-fitting portion 12 of the pin 8 press-fitted into the second through-hole 7 is in close contact with the press-fitting surface 7c of the second through-hole 7 on both the tip end side and the proximal end side of the annular groove 13. By doing so, the pin 8 in the second through hole 7 is fixed without being tilted with respect to the central axis L2.

Note that FIG. 5 shows a modified example of the annular groove formed on the pin. The pin 18 shown in FIG. 5 is provided at a position where the formation position of the annulus groove 19 is deviated from the annulus groove 13 of the first embodiment along the central axis L2 in the direction of the proximal end portion . A part of the annular groove 19 is formed at a position corresponding to the press-fitting surface 7c of the second through hole 7, and has the same configuration as the pin 8.

Specifically, in the annular groove 19 of FIG. 5, the tip portion 19a is formed at a position corresponding to the press-fitting surface 7c of the second through hole 7, and the proximal end portion 19b is the proximal end portion of the second through hole 7. It is formed on the proximal end side of the pin 8 along the central axis L2 with respect to 7d. As a result, the press-fitting portion 20 of the pin 18 to be press-fitted into the second through hole 7 has a base end portion 21a of the pin side surface taking portion 21 formed so as to be inclined in the same manner as the pin side surface taking portion 11 of the first embodiment. , The portion near the base end portion 7d of the press-fitting surface 7c of the second through hole 7 formed between the tip portions 19a of the annular groove 19 is radial toward the annular groove 19 after passing through the press-fitting portion 20. Elastically returns to the inside. The elastic return portion 22 formed by elastically returning toward the annular groove 19 penetrates into the annular groove 19 while engaging with the tip portion 19a of the annular groove 19 of the pin 18.

In the pin 18 shown in FIG. 5, the press-fitting portion 20 is press-fitted and fixed to the press-fitting surface 7c of the second through hole 7, and the elastic return portion 22 of the elongated hole forming wall 5 that has penetrated into the annular groove 19 is at the tip thereof. By engaging with the portion 19a in a pressed state, it is prevented from coming off toward the proximal end side along the central axis L2, so that it is more firmly fixed to the second through hole 7 of the elongated hole forming wall 5.

Next, a second embodiment relating to the structure for assembling the rolling roller to the piston rod will be described with reference to FIGS. 6 and 7 . In FIG. 7 and FIG. 8 described later, the description of the rolling roller 34 is omitted for convenience of explanation. In the assembly structure of the second embodiment, the shape of the pin 28, the shape of the rolling roller 34 corresponding to the pin 28, and the inner diameter of the first through hole 6'of the elongated hole forming wall 4'in which the pin 28 is inserted are different. In addition to being different from the shape of the pin 8 of the first embodiment, the inner diameter of the first through hole 6 formed in the elongated hole forming wall 4, and the shape of the rolling roller 10, it has the same configuration as that of the first embodiment. Therefore, only the pin 28, the first through hole 6'of the slotted hole forming wall 4', and the rolling roller 34 will be described.

As shown in FIGS. 6 and 7, the pin 28 has a tapered pin side surface portion 29 on the outer peripheral edge portion of the tip portion 28a. Further, the pin side chamfer portion 29 is formed so as to have an inclination of about 30 ° with respect to the direction along the central axis L2 of the pin 28, and the chamfer tip portion 29a of the pin side chamfer portion 29 and the pin side chamfer portion 29. The chamfering base end portion 29b is formed as an arc portion by separately chamfering. The chamfered base end portion 29b having an arc shape does not generate a local frictional force with the press-fitting surface 7c of the second through hole 7, so that thread burrs are not formed on the press-fitting surface 7c. It is more desirable than the pin chamfer portion 11 formed on the pin 8 of 1 embodiment.

Further, as shown in FIGS. 6 and 7, a press-fitting portion 30 is formed adjacent to the pin side surface taking portion 29 of the pin 28, and the press-fitting portion 30 has an outer circumference centered on the central axis L2 of the pin 28. A concave annular groove 31 is formed so as to go around the surface, and a large diameter portion 32 is formed adjacent to the base end portion 30a of the press-fitting portion 30. The annular groove 31 faces the press-fitting surface 7c of the second through hole 7 in the entire area, and the large diameter portion 32 has an outer diameter larger than the outer diameter of the tip portion 28a of the pin 28, that is, the outer diameter d1 of the press-fitting portion 30. It is formed to have d2. Further, the tip end portion 32a of the large diameter portion 32 adjacent to the base end portion 30a of the press-fitting portion 30 is located at a position separated from the tip end portion 28a of the pin 28 in the proximal end portion by the thickness t1 of the elongated hole forming wall 5. It is formed and functions as a retaining pin 28 in the direction toward the tip of the second through hole 7.

The concave annular groove 31 shown in FIGS. 6 and 7 press-fits the elastic return portion 33 formed by the press-fit surface 7c into close contact with the press-fit portion 30 of the pin 28 when the press-fit portion 30 is press-fitted into the second through hole 7. As such, the elastic return portion 33 is formed to be shallower than the projecting length inward in the radial direction. Further, the axial length of the annular groove 31 is formed shorter than t1-h2 when the axial length of the pin side chamfer portion 29 is h2, and the tip portion 31a and the base end portion of the annular groove 31 are formed. It is desirable that 31b is formed so as not to be adjacent to the chamfer base end portion 29b and the base end portion 30a of the press-fitting portion 30, respectively. In that case, the press-fitting portion 30 of the pin 28 press-fitted into the second through hole 7 comes into close contact with the press-fitting surface 7c on both the tip end side and the proximal end side of the annular groove 31 so as to be in close contact with each other. The pin 28 in the through hole 7 is fixed without being tilted with respect to the central axis L2.

Further, as shown in FIGS. 6 and 7, the second through hole 7 of the elongated hole forming wall 5 having the same shape as that of the first embodiment is pressed against the pin 28 because the tip of the pin 28 is press-fitted. The inner diameter D2 is formed to be smaller by a minute length than the outer diameter d1 of the pin 28. Further, the first through hole 6'of the elongated hole forming wall 4'and the inscribed hole 35 of the rolling roller 34 shown in FIG. 6 are intermediate with respect to the pin because it is sufficient that the large diameter portion 32 of the pin 28 can be inserted. The inner diameter D1'of the first through hole 6'and the inscribed circle diameter D3'of the inscribed hole 35 (the inner diameter of the inner ring 34b inscribed with the pin 28) are passed through the second through the first through hole 6'so as to be a fit or a gap fit. It is formed to be larger than the inner diameter D2 of the hole 7 and to be the same as or slightly larger than the outer diameter d2 of the large diameter portion 32 of the pin 28. The rolling roller 34 is a rolling bearing, and may be supported while being in contact with the outer peripheral surface of the pin 28 by the rolling element 34a without having an inner ring, as in the roller 10 of the first embodiment. ..

Assembling the rolling roller 34 to the piston rod by the pin 28 shown in FIGS. 6 and 7 is performed as follows. First, the rolling roller 34 is made into a long hole while aligning the inscribed hole 35 of the rolling roller 34 with the first through hole 6'and the second through hole 7 of the pair of long hole forming walls (4', 5). Place it between the 3'slotted hole forming walls (4', 5). Next, the tip portion 28a of the pin 28 and the large diameter portion 32 are inserted in order from the first through hole 6'of the elongated hole forming wall 4'to the inscribed hole 35 of the rolling roller 34, and finally the large diameter portion 32. The tip portion 28a of the pin 28 is inserted into the second through hole 7 of the slotted hole forming wall 5 until the tip portion 32a of the pin 28 abuts on the inner peripheral surface 5b of the slotted hole forming wall 5. Since the inner diameter D2 of the second through hole 7 is formed so as to be tightly fitted to the pin 28, the pin 28 is press-fitted so that the tip portion 28a is flush with the outer peripheral side opening portion 7a. The portion 30 is press-fitted into the press-fitting surface 7c of the second through hole 7. In the pin 28, the press-fitting portion 30 is press-fitted and fixed to the press-fitting surface 7c of the second through hole 7, and the tip portion 28a is flush with the outer peripheral side opening 7a of the second through hole 7 by the large diameter portion 32. It is prevented from coming off in the direction of the tip while being prevented from coming off. The rolling roller 34 is rotatably supported by the large diameter portion 32 of the pin 28.

As shown in FIG. 7, when the press-fitting portion 30 of the pin 28 is press-fitted into the second through hole 7, the second through-hole 7 has the inner peripheral wall on the tip side of the chamfer base end portion 29b in the tip direction by the press-fitting portion 30. By being pressed against, a bulge is generated in the vicinity of the base end portion of the hole chamfer portion 7b. However, the swelling generated in the hole side surface removing portion 7b is formed in the accommodating area 36 of the second through hole 7 formed between the hole side surface removing portion 7b and the pin side surface removing portion 29 inside the second through hole 7. Since it stays and does not protrude from the outer peripheral surface 5a of the slotted hole forming wall 5 of the piston rod, it does not interfere with the sliding of the piston rod.

On the other hand, as shown in FIGS. 6 and 7, the press-fitting surface 7c, which is the inner peripheral wall of the second through hole 7, has a pin press-fitting portion on the base end side of the chamfering base end portion 29b of the pin side chamfering portion 29. The portion 30 elastically deforms outward in the radial direction of the pin 28, and a part of the press-fitting surface 7c is formed after passing through the tip-side press-fitting portion (the portion between the chamfering base end portion 29b and the tip portion 31a of the annular groove 31). , Elastically returns inward in the radial direction toward the annulus groove 31. The elastic return portion 33 formed by returning toward the annular groove 31 engages with the opening edge portion of the annular groove 31 of the pin 28, that is, the tip portion 31a and the base end portion 31b in a pressed state. The tip of the elastic return portion 33, which invades the inside of the annular groove 31 and protrudes inward in the radial direction of the pin 28, is pressed against the bottom portion 31c of the annular groove 31 and comes into close contact with each other. In the pin 28, the elastic return portion 33 is pressed and engaged with both the tip portion 31a and the base end portion 31b of the annulus groove 31, so that the pin 28 exerts a retaining action with respect to the central axis L2 and also exerts an annular ring. The tip portion that has penetrated into the groove 31 is in close contact with at least a part of the inner peripheral surface of the annular groove 31 including the bottom portion 31c, whereby the swing of the elongated hole forming wall 5 with respect to the second through hole 7 is suppressed. It is fixed more firmly.

Note that FIG. 8 shows a modified example of the pin side surface taken portion formed on the pin 28 of the second embodiment. The pin 38 shown in FIG. 8 has an outer peripheral edge of the tip 38a, unlike the pin side picking portion 29 of the second embodiment, in which the tip portion and the base end portion of the tapered pin side surface portion are formed in an arc shape. It has a pin side surface taking portion 38b having an arc shape as a whole, and the shape of the pin side surface taking portion 38b is different, and has the same configuration as the pin 28 of the second embodiment.

As shown in FIG. 8, the pin side surface taking portion 38b formed so as to have an arc shape as a whole is a group that is continuous with the press-fitting portion 30 at the base end portion 38c and is in contact with the press-fitting surface 7c of the second through hole 7. The end 38c does not generate a local frictional force with the press-fitting surface 7c, so that the thread burr does not form or is difficult to form on the press-fitting surface 7c. It is more desirable than the formed pin side surface portion 11. Further, as shown in FIG. 8, when the press-fitting portion 30 of the pin 38 is press-fitted into the second through hole 7, the inner peripheral wall on the tip side of the base end portion 38c of the second through-hole 7 is in the tip direction by the press-fitting portion 30. By being pressed against, a swelling is generated in the vicinity of the base end portion of the hole side surface portion 7b. However, the swelling generated in the hole side surface removing portion 7b is formed in the accommodating area 39 of the second through hole 7 formed between the hole side surface removing portion 7b and the pin side surface removing portion 38b inside the second through hole 7. Since it stays and does not protrude from the outer peripheral surface 5a of the slotted hole forming wall 5 of the piston rod, it does not interfere with the sliding of the piston rod.

The large diameter portion 32 formed on the pin 28 of the second embodiment is formed so as to be adjacent to the base end portion 12a of the press-fitting portion 12 of the pin 8 of the first embodiment, whereby the tip of the pin 8 is formed. It may be used as a stopper in the direction.

1 Piston rod 2 Piston 3,3'Elongated hole 4,4', 5 Elongated hole forming wall 6,6' 1st through hole 7 2nd through hole 7b Hole side surface taking part 7c Press-fit surface 8 Pin 8a Tip 9 Inscribed Hole 10 Rolling roller 11 Pin side taking part 12 Press-fitting part 13 Circular groove 15 Elastic return part 18 Pin 19 Circular groove 20 Press-fitting part 21 Pin side taking part 22 Elastic return part 28 Pin 29 Pin Side-cutting part 29a Take-out tip Part (arc part)
29b Chamfer base end (arc part)
30 Press-fitting part 31 Circular groove 32 Large diameter part 32a Tip part 33 Elastic return part 34 Rolling roller 35 Inscribed hole 38 Pin 38b Pin side surface taking part (arc part)
38c Base end D1, D1'Inner diameter of first through hole D2 Inner diameter of second through hole D3, D3' Inscribed circle diameter of inscribed hole

Claims (4)

A pair of piston rods integrated with a piston that slides in the cylinder in the axial direction, a long hole provided in the piston rod that penetrates in a direction orthogonal to the piston rod, and a pair of long holes that face each other across the long hole. The first through hole and the second through hole extending in the direction orthogonal to the axis of the piston rod provided on the elongated hole forming wall, respectively, and the pin press-fitted and fixed to the second through hole rotate via the inscribed hole. A rolling roller that is freely supported is provided, and the inner diameter of the second through hole is formed to be smaller than the inner diameter of the first through hole and the inscribed circular diameter of the inscribed hole provided in the rolling roller. With the rolling roller arranged so that the first through hole to the inscribed hole are all aligned between the pair of elongated hole forming walls, the pin is inserted in the order of the first through hole and the inscribed hole, and further. The structure is such that the tip of the pin is press-fitted into the second through hole to assemble the rolling roller to the piston rod.
A tapered hole side surface portion is provided around the inner peripheral edge of the second through hole where the tip of the press-fitted pin is exposed, and the outer peripheral edge of the tip of the pin is tapered. A structure for assembling a rolling roller to a piston rod, characterized in that an arc-shaped pin side surface including an arc portion is provided around the shape or at least the contact portion of the second through hole with the inner peripheral surface. A tapered pin side surface portion is formed at the tip end portion of the pin, and the taper angle of the pin side surface edge portion is set to 60 ° or less, preferably 40 ° or less. Item 1. The structure for assembling the rolling roller to the piston rod. The pin is formed around the press-fitting portion formed adjacent to the base end portion of the pin side surface taking portion at a position corresponding to the press-fitting surface of the second through hole into which the pin is press-fitted, and the outer periphery of the press-fitting portion. Has an annulus groove to be installed,
The rolling roller according to claim 1 or 2, wherein the elastic return portion formed on the press-fit surface of the second through hole penetrates and engages with the annular groove by passing through the press-fit portion. Assembled structure to the piston rod. On the pin, which is the bearing shaft of the rolling roller, a large diameter portion larger than the outer diameter of the tip portion of the pin is continuously formed on the base end side of the annular groove, and the tip of the large diameter portion is formed. 3 is the rolling roller according to claim 3, wherein the pin is formed at a position where it abuts on the peripheral edge of the base end of the second through hole when the pin is press-fitted into the second through hole. Assembly structure to the piston rod.

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