JP3281952B2 - Forming method of connecting belt for rolling element connecting body and forming die used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling element circulating path such as a linear guide device in which a plurality of rolling elements such as balls and rollers arranged in a row are held rotatably by a connecting belt. The present invention relates to a method of forming the above-mentioned connecting belt in a rolling element connected body used in the above, and a forming die used in the method.

[0002]

2. Description of the Related Art A ball chain (ball joint) disclosed in Japanese Patent Application Laid-Open No. 5-52217 is an example of this kind of rolling element joint. In this ball chain, a large number of balls arranged in a row are rollably held by a resin-made connecting belt formed by connecting holding members (intervening portions) interposed between the balls by connecting members. The connection belt is formed integrally with the ball by inserting the ball as a core into a mold.

[0003] However, in this ball chain, a small gap is formed between the ball and the holding member by shrinkage at the time of resin curing after injection molding to provide the ball with rotation. It is difficult to obtain it reliably, and depending on the type of resin, rotation may not be obtained.

To solve this problem, as proposed in Japanese Patent Application Laid-Open No. 9-14264,
Resin linked body (connecting belt) injection molded integrally with ball
There is also a method of forming a gap for rotation between the resin connected body and each ball by oil absorption or water absorption treatment after release, but the process of applying these oil absorption or water absorption treatment after release is complicated. In addition to lower productivity and higher costs,
Because of the great restrictions on the selection of the resin material, it is difficult to form a desired gap with a resin having a desired strength and obtain smooth rotation.

[0005] Further, since the above-mentioned problem is caused by integrally forming the connecting belt by using the balls constituting the ball chain as they are, an example is disclosed in Japanese Patent Application Laid-Open No. Hei 10-238539. As described above, using a mold provided with ball dies protruding in a line in a molding dies, forcibly pulling out the ball dies from between the ball holding members (interposed portions) after injection molding, and It is also conceivable to push another small-diameter ball into a ball chain product.

However, in this method, since each ball mold is fixed to the mold, it is necessary to pull out the ball mold from between the ball holding members which are concave on both sides and are fitted on the side faces of the ball mold. A large force is required, and unless the resin is too soft, the ball holding member will be plastically deformed or damaged, and if it is made of too soft resin, the ball will fall due to insufficient ball holding force in the assembled product. It has many problems, such as being easy and the strength of the connecting member being insufficient.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and it is possible to quickly and easily release a connecting belt after injection molding from a mold, and a post-processing step is not required. It is an object of the present invention to provide a method of forming a connecting belt for a rolling element connected body with high productivity and a forming die used in the method.

It is another object of the present invention to form a gap between a rolling element and a connecting belt without fail so as to provide the rolling element with good rotational properties and to use a resin material constituting the connecting belt. An object of the present invention is to provide a method of forming a connecting belt for a rolling element connecting body, which requires less kinds of restrictions, and a forming die used in the method.

[0009]

A method of forming a connecting belt for a rolling element connecting body according to the present invention comprises a step of forming an interposing portion interposed between a plurality of rolling elements arranged in a line at a predetermined interval. In a molding method for molding a connecting belt for a rolling element connected body, which is connected by a flexible connecting portion, by injection molding, a base provided on a protruding plate, a recess provided on a movable mold plate and a fixed mold plate. The rolling element for molding fixed to the tip of the attached protruding pin is
Injection molding in the state of being fitted as a core, and when the mold is opened, the longitudinal end of the molded product protruding from the movable mold plate together with each of the molding rolling elements is gripped and pulled in the direction in which the connecting portion is curved, The interposer is sequentially drawn out from between the adjacent rolling elements while elastically deforming the protruding pins to the side to obtain the connection belt.

Further, in the molding die of the present invention, interposed portions interposed between a plurality of rolling elements arranged in a line at a predetermined interval are connected by a flexible connecting portion. A mold for molding a connecting belt for a rolling element connecting body by injection molding, wherein the interposed portion and the cavity for forming the connecting portion are formed on divided surfaces of an upper mold plate and a lower mold plate. A recess for fitting a rolling element for use as a core is provided, and the rolling element for forming is fixed to a tip end of a projection pin made of an elastic material having a base attached to a projection plate.

In the present invention, as the elastic material constituting the protruding pin, for example, various metallic materials such as steel materials, heat-resistant plastics and glass fibers can be used.

According to the present invention, the connecting belt that is injection-molded integrally with the forming rolling element allows the interposed portion to be pulled out of the interposed portion while elastically deforming the protruding pin to which the forming rolling element is attached to the side. By doing so, it is possible to quickly and easily release the rolling element from the molding with a small force, and there is no need for a post-processing step such as oil absorption or water absorption processing for imparting rotation to the rolling element as in the conventional method. The process is simple and high productivity is obtained.

The rolling elements for molding in the present invention include:
A ball or a roller can be used according to the rolling elements constituting the rolling element linking body, and the rolling element for forming may have the same diameter as the rolling element. As described in the invention described above, if a rolling element having a diameter larger than that of the rolling element linking body is used as the rolling element for molding, the rolling element incorporating the rolling element between the interposed portions of the manufactured connection belt is used. In the moving body connected body, a gap can be reliably formed between the rolling element and the interposed portion, thereby obtaining good rotation properties, and the resin forming the connecting belt is formed by the resin for forming the gap. It is particularly preferable because the material type is not restricted and a connecting belt having desired strength, abrasion resistance and flexibility can be obtained by freely selecting a resin.

In the present invention, the base of the protruding pin to which the rolling element for molding is attached may be fixed to the protruding plate, but the base of the protruding pin may extend in the longitudinal direction. With the configuration in which the interposed portion is pulled out from between the rolling elements for molding, the rolling elements for molding of the drawn-out section are pulled out together with the protruding pins when the interposed portion is pulled out from the rolling elements for molding. Is performed more smoothly and quickly, which is particularly preferable.

In the present invention, the protruding pin may be
A rod having a uniform cross-sectional shape may be used. With this configuration, when the interposed portion is pulled out from between the rolling elements for molding, the upper portion of the protruding pin is greatly elastically deformed to the side, so that the interposed portion can be more easily pulled out, which is particularly preferable.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to a first example shown in FIGS. In FIG. 1, 1
Is a rolling element connected body (ball chain) using the balls 2 as rolling elements, and a plurality of balls 2 arranged in a line.
Are rotatably held by the connection belt 3. As shown in FIG. 1 to FIG. 4, the connecting belt 3
It is manufactured by connecting the interposing portion 4 interposed therebetween by a connecting portion 5 having flexibility, and injection molding resin. The interposition part 4 has a disk shape, and has a partially spherical concave surface part 4 a on a side surface of the interposition part 4 to which the side surface of the ball 2 fits.

5 to 7 show a molding die 10 for injection molding the connecting belt 3, FIGS. 5 and 6 show a mold closed state, and FIG. 7 shows a mold open state. The molding die 10 includes a fixed die 12 attached to a fixed plate 11 of an injection molding machine (not shown) and a movable die 22 attached to a movable plate 21.
And a molding ball (molding rolling element) 34, which will be described later, fixed to the distal end of a projection pin 33 having a base attached to the projection plate 30.

The fixed mold 12 comprises a fixed mounting plate 13 and a fixed mold plate 14, and the movable mold 22 comprises a movable mounting plate 23, a spacer block 24 and a movable mold plate 25. . A concave portion for forming the cavity 15 for forming the interposition portion 4 and the connecting portion 5 is formed on the dividing surface 14a of the fixed-side template 14 and the dividing surface 25a of the movable-side template 25, and a molding ball. There are provided recesses 16 and 26 into which 34 is fitted. A known hot water supply path from the nozzle of the injection molding machine to the runner of the sprue bush and the cavity 15 through the runner is formed in the fixed mold 12. Has been omitted.
Reference numeral 27 denotes a projecting rod hole.

Reference numeral 30 denotes a protruding plate housed in the space behind the movable mold plate 25, which is formed by stacking an upper plate 31 and a lower plate 32,
A molding ball (forming rolling element) 34 is fixed to the tip of a projection pin 33 having a base attached to the projection plate 30. In this example, as the molding ball 34, a steel ball having a diameter larger than that of the ball 2 constituting the rolling element connected body 1 is used. It is selected such that a desired amount of gap is formed between the second member 2 and the concave portion 4a of the interposition portion 4 (and the inner edge portion of the connecting belt 3 facing the outer periphery of the ball 2). The shapes and dimensions of the recesses 16 and 26 are also determined so that the molding balls 34 are fitted with a small gap when the mold is closed.

The protruding pin 33 is made of steel, and its base is attached to the protruding plate 30 so as to be movable by a predetermined amount in the longitudinal direction of the pin. That is, as shown in FIGS. 6 to 8, the protruding pin 33 is slidably fitted to the upper plate 31 of the protruding plate 30 and the groove-shaped space 36 between the upper plate 31 and the lower plate 32.
The horizontal bar 37 inserted therein is vertically movably fitted in an elongated hole 38 provided at the base of each protruding pin 33, whereby the protruding pin 33 is inserted into the groove-shaped space 36. The bottom surface restricts the movement of the protruding plate 30 in the pushing direction, and together with the protruding pin 33 (supported by the lower end of the elongated hole 38), the horizontal bar 37 raised as shown by a chain line 39 in FIG. The movement with respect to the protruding plate 30 in the pull-out direction is restricted by the engagement with the protruding plate 30.

Numeral 40 denotes a small-diameter portion provided near the tip of the protruding pin 33, which protrudes from the bottom surface of the concave portion 26 of the movable mold plate 25 when the protruding pin 33 shown in FIG. Further, the small diameter portion 40 is provided.

Next, a molding method for molding the connecting belt 3 by the molding die 10 having the above-described configuration will be described. First, with the mold closed as shown in FIG. 6 and the molding ball 34 fitted as a core in the recess 16 of the fixed mold plate 14 and the recess 26 of the movable mold plate 25, the molten resin is cast in a usual manner. Tea 15
It is injected into the inside, and is subjected to pressure-holding and cooling to perform injection molding.

Next, the mold is opened as shown in FIG. 7, the projecting plate 30 is stopped at a predetermined position by a projecting rod (not shown), and the connecting belt 3 formed integrally with the molding ball 34 at the tip of the projecting pin 33 is moved. Movable mold plate 25 (divided surface 25a)
More protruding.

Next, the longitudinal end 3a of the connecting belt 3 is gripped by a chuck 41 attached to the tip of a robot arm or the like (not shown), and the connecting portion 5 is bent upward as indicated by an arrow R. When pulled, this bending causes the adjacent interposition portions 4, 4 to open in a C-shape so that the lower end portion is widened, so that the molding ball 34 can be easily separated from the interposition portions 4, 4. Since the molding ball 34 which is about to be detached by the lifting of the interposition part 4 is elastically deformed at the upper part of the protruding pin 33 toward the side indicated by the arrow F, the interposition part 4 is not subjected to a large resistance force. Adjacent molding balls 3
It is quickly and easily withdrawn from between 4,34.

Then, the chuck 41 is driven in the direction of arrow T to sequentially curve the connecting portion 5 in the vicinity of the interposed portion 4 to be pulled out, so that each interposed portion 4 is sequentially formed from the longitudinal end 3a side. Thus, the connecting belt 3 pulled out from the forming ball 34 and released from the forming ball 34 as shown in FIG. 2 is obtained.

At this time, in this example, since the protruding pin 33 has the small-diameter portion 40, the upper portion of the protruding pin 33 is greatly elastically deformed, and the pulling out of the interposition portion 4 is further facilitated. Since the molding ball 34 is attached to the protruding plate 30 so as to be movable by a predetermined amount in the longitudinal direction, the molding ball 34 near the draw-out portion of the interposition portion 4 is driven by the pull-out force of the interposition portion 4 and moves together with the protruding pin 33 by the arrow P. Since it moves in the pull-out direction indicated by, the pull-out of the interposition unit 4 is further facilitated. Even if the horizontal bar 37 rises to the lower surface of the upper plate 31 due to the movement of the protruding pin 33 in the pulling-out direction, the protruding pin 33 that supports another molding ball 34 before the interposed portion 4 is pulled out is not moved horizontally. The rod 37 only moves in the elongated hole 38, is maintained at the lowered position shown in the drawing, and is in a state in which the interposition unit 4 is ready for withdrawal.

If the ball 2 is inserted between the interposed portions 4 while the connecting portion 5 is bent in the same manner as described above with respect to the connecting belt 3 thus obtained, the rolling member connected member shown in FIG. 1
Is obtained, and a gap is reliably formed between the ball 2 and the concave surface portion 4a of the interposition portion 4, so that good rotation properties can be obtained.

It should be noted that, instead of the mounting structure of the base of the projecting pin 33 to the projecting plate 30 in the above example, for example, FIG.
As shown in FIG. 5, a flange 45 is fixed to the lower end of the protruding pin 33, and the flange 45 may have a mounting structure for restricting the amount of movement of the protruding pin 33 with respect to the protruding plate 30 in the pulling-out direction. However, if the material and the size are sufficiently rich in elasticity, the base of the protruding pin 33 may be fixed to the protruding plate 30 or the provision of the small diameter portion 40 may be omitted.

Although the connecting belt 3 for the rolling element connecting body 1 using the ball 2 as the rolling element has been described above, the present invention relates to a roller as a rolling element as in the second example shown in FIGS. The present invention can also be applied to the formation of a connection belt 53 of a rolling element connection body (roller chain) 51 using 52. In this case, the connection belt 53 is formed by connecting an interposition portion 54 interposed between the adjacent rollers 52 by a flexible connection portion 55, and the interposition portion 54 has a rectangular plate shape and a side surface thereof. Is formed with a concave portion 54a in the form of a partial cylindrical surface into which the side surface of the roller 52 fits.

In order to form the connecting belt 53, instead of the forming ball 34 of the first example, a forming roller (forming roller) having a larger diameter (and a wider width) than the roller 52 is used.
By using 56 to make the concave portion 26 of the molding die 10 conform to the shape of the molding roller 56 and making the cavity 15 suitable for molding the interposition portion 54 and the connecting portion 55, the first The connection belt 53 can be obtained by the same method as the example.

In this case, it is necessary to provide a detent for preventing the protruding pin 33 of the forming roller 56 from rotating around the axis thereof. Therefore, except when the base of the protruding pin 33 is fixed to the protruding plate 30. Thus, the direction of the forming roller 56 may be restricted by making the projecting pin 33 have a rectangular cross section, or by using two projecting pins 33 as shown by a chain line in FIG.

The present invention is not limited to the above examples. For example, the concrete structure of the molding die and each part thereof may be other than those described above, and the connecting belt also has a reinforcing material inside, for example. Its structure and shape may be other than those described above. In the above example, the rolling element for molding has a larger diameter than the rolling element forming the linked rolling element. However, depending on the type of the resin forming the connecting belt, the interposed portion is formed by shrinkage after injection molding. When an appropriate gap is formed between the rolling element and the rolling element, the forming rolling element may have the same diameter as the rolling element. In addition, withdrawal of the injection molded product from between the rolling elements for molding,
It may be performed manually.

[0033]

As described above, according to the present invention,
The rolling element for molding is fixed to the tip of a protruding pin having a base attached to a protruding plate, and the interposed portion is held while elastically deforming the protruding pin by gripping the longitudinal end of the injection molded product protruded when the mold is opened. Are sequentially pulled out from the rolling elements for molding, so that the connecting belt can be quickly and easily released from the mold (especially, the rolling elements for molding) with a small force, and post-processing for imparting rotation to the rolling elements. Since no process is required, the process is simple and high productivity can be obtained.

In addition to the above-described effects, according to the second and fourth aspects of the present invention, in the rolling element connecting body in which the rolling element is incorporated in the connecting belt, a clearance between the rolling element and the connecting belt can be ensured. In this way, the rolling element can be provided with good rotational properties, and the type of resin of the connecting belt can be less restricted.

In addition to the above effects, according to the fifth and sixth aspects of the present invention, it is possible to more easily pull out the interposed portion from the rolling element for molding.

[Brief description of the drawings]

FIGS. 1A and 1B show a rolling element connected body according to a first example of an embodiment of the present invention, wherein FIG. 1A is a front view in which an intermediate portion is omitted, and FIG. .

FIG. 2 is a front view in which an intermediate portion of a connecting belt in FIG. 1 is omitted.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a vertical sectional view of a main part of a mold for forming a connecting belt in FIG. 2;

FIG. 6 is an enlarged vertical sectional view of a main part of FIG.

7 is a diagram corresponding to FIG. 6 when the mold of FIG. 5 is opened.

8 is a sectional view taken along line CC of FIG. 7;

9 is a view corresponding to FIG. 8, showing another embodiment of the mounting mechanism of the base of the protruding pin in FIG. 7;

FIG. 10 is a diagram corresponding to FIG. 1 showing a rolling element linked body according to a second example of an embodiment of the present invention;

FIG. 11 is a front view of the connecting belt in FIG. 10;

FIG. 12 is a sectional view taken along line DD of FIG. 11;

FIG. 13 is a sectional view taken along line EE of FIG. 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rolling body connection body, 2 ... Ball (rolling body), 3 ... Connection belt, 4 ... Interposition part, 5 ... Connection part, 10 ... Mold for molding, 1
4 ... fixed side mold plate, 14a ... division surface, 15 ... cavity, 16 ... concave part, 25 ... movable side mold plate, 25a ... division surface,
26 ... recess, 30 ... projecting plate, 33 ... projecting pin, 34 ... molding ball (forming rolling element), 37 ... horizontal bar, 38 ... elongated hole, 40 ... small diameter part, 51 ... rolling element linked body, 52 ... rollers (rolling elements), 53 ... connecting belt, 54 ... interposed part, 55 ...
Connecting portion, 56: forming roller (forming rolling element).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/84 B29C 33/44-33/54 F16C 29/06

Claims (6)

(57) [Claims] 1. A connection for a rolling element connecting body in which interposed parts interposed between a plurality of rolling elements arranged in a line at a predetermined interval are connected by a flexible connecting part. In a molding method for molding a belt by injection molding, a molding rolling element fixed to a tip of a protruding pin having a base attached to a protruding plate in a recess provided in a movable side template and a fixed side template is used as a core. Injection molding is performed in the fitted state, and when the mold is opened, the longitudinal end of the molded product protruding from the movable mold plate together with the molding rolling elements is gripped and pulled in a direction in which the connecting portion is curved, and the projecting pin is Forming the connecting belt by successively pulling out the interposed portions from between the adjacent forming rolling elements while elastically deforming the connecting side. 2. The rolling element according to claim 1, wherein the rolling element for molding has a diameter larger than that of the rolling element inserted between the interposed portions and constituting the linked body of rolling elements. A method for forming a connection belt for a connection body. 3. A rolling element connecting body connection in which interposed portions interposed between a plurality of rolling elements arranged in a line at a predetermined interval are connected by a flexible connecting portion. A mold for molding a belt by injection molding, wherein a cavity for forming the interposed portion and the connecting portion, and a molding roller used as a core are formed on divided surfaces of an upper mold plate and a lower mold plate. A molding die, comprising a concave portion for fitting a moving body, and wherein the rolling element for molding is fixed to a tip end of a projection pin made of an elastic material having a base attached to a projection plate. 4. The molding die according to claim 3, wherein the rolling element for molding has a diameter larger than that of the rolling element inserted between the interposed portions and constituting the linked body of rolling elements. 5. The molding die according to claim 3, wherein a base of the protruding pin is attached to the protruding plate so as to be movable by a predetermined amount in a longitudinal direction. 6. The molding die according to claim 3, wherein a small-diameter portion is provided at a portion of the protruding pin that protrudes from a bottom surface of the concave portion of the movable mold plate when protruding.