JP4744456B2 - Driving device belt tensioning method and driving device - Google Patents

Description

The present invention relates to a belt tensioning method for a driving device and a driving device. The drive device according to the present invention may be any device that transmits power by driving a belt between the pulley of the drive shaft and the pulley of the driven shaft, such as an injection molding machine, a press, and a machine tool that performs metal processing. Applies to machines and other mobile machines. And as a driven shaft, it applies especially to what converts the rotational motion of a driven shaft into a linear motion, and a ball screw, a ball nut, etc. are assumed as an example. The number of driven shafts is particularly effective for those having two or more driven shafts.

Patent Document 1 and Patent Document 2 are known as those that apply tension to a belt of an injection device of an injection molding machine that is a kind of drive device. In both Patent Document 1 and Patent Document 2, a tension roller (idler wheel) is provided to apply tension to the belt. However, Patent Document 1 and Patent Document 2 do not describe in what state the pulley of the driven shaft for applying tension to the belt should be applied.

When tension is applied to the belt, a force is exerted on the pulley of the driven shaft, causing the following problems. That is, as shown in FIG. 4 which is an explanatory diagram of the conventional method, when tension is applied to the belt 13 with the pulleys 11a and 111b fixed to the driven shafts 12a and 12b, the arrow of the pulley 15 of the drive shaft 14 Due to the movement in the A direction, the belt 13 is pulled in the directions of arrows B and C, respectively, and the pulleys 11a and 11b and the driven shafts 12a and 12b rotate in the opposite directions (arrows D and E directions), respectively. When the driven shafts 12a and 12b are ball screws, when the ball screws 12a and 12b are rotated in opposite directions (arrows D and E directions) as shown in FIG. Both ends of the movable member 17 to which the ball nuts 16a and 16b into which the 12b is inserted are attached are moved in opposite directions (in the directions of arrows F and G), and the parallelism with the fixed member 18 is distorted. .

As shown in FIG. 6 which is an explanatory view of another conventional method, the drive shaft 24 is moved in the H direction in a state where the pulleys 21a and 21b are not fixed to the driven shafts 22a and 22b, and the belt 23 A method of applying tension is also conceivable. However, in the method of FIG. 6, when the belt 23 is pulled in the directions of arrows I and J, radial loads are applied to the driven shafts 22a and 22b via the pulleys 21a and 21b, and the shaft cores and pulleys of the driven shafts 22a and 22b are applied. The shaft centers of 21a and 21b are slightly shifted. And even if the pulleys 21a and 21b are fixed to the driven shafts 22a and 22b in that state, the pulleys 21a and 21b are attached concentrically to the driven shafts 22a and 22b as a result of the strong radial load. Can not. Therefore, even if the driven shafts 22a and 22b are driven via the belt 23 by a driving motor (not shown) in such a state, there is a problem that the apparatus generates vibrations or the life of the belt 23 is reduced. Also, as a compromise, the belt is tensioned to the driven shaft after the pulley is weakly fixed, and the belt is tensioned and the belt is tensioned and the pulley is fixed to the driven shaft alternately. Although it is conceivable to carry out the installation work, it is necessary to make fine adjustments by a skilled worker, and the belt installation work cannot always be performed satisfactorily.

JP 2003-120769 A (Claim 1, FIG. 1) JP 2003-266499 A (Claim 1, FIG. 1)

In the present invention, in view of the above-described problems, when tension is applied to the belt stretched between the pulley of the driven shaft and the pulley of the drive shaft, it is possible to perform a good belt tensioning operation that does not cause problems during operation. An object of the present invention is to provide a belt tensioning method for a driving device and a driving device.

According to a first aspect of the present invention, there is provided a belt tensioning method for a driving device, in which a driving shaft connected to a driving motor and a driven shaft are arranged, and the belt is hung between the pulley of the driving shaft and the pulley of the driven shaft. In the belt tensioning method of the passed drive device, a pulley having a bearing disposed on the inner peripheral side is rotatably attached to the driven shaft via the bearing, and the belt spanned between the pulley and the pulley of the drive shaft is mounted on the belt. The pulley and the driven shaft are fixed by a fixing member in a state where tension is applied.

According to a second aspect of the present invention, there is provided a belt tensioning method for a driving device according to the first aspect, wherein a pulley having a bearing disposed on the inner peripheral side is rotatably attached to a plurality of driven shafts, respectively. The pulley and the driven shaft are fixed by a fixing member in a state where tension is applied to the belt that is stretched between the pulleys and the pulley of the drive shaft.

A belt tensioning method for a driving device according to a third aspect of the present invention is characterized in that, in the first or second aspect, the belt tensioning method is used for an injection device of an injection molding machine.

According to a fourth aspect of the present invention, there is provided a drive device in which a plurality of driven shafts for converting a rotational motion into a linear motion and a bearing opposed to the driven shaft on the inner peripheral side are disposed and fixed before the driven shaft. A pulley that is rotatably provided with respect to the shaft and is tensioned to a belt that is next stretched, and is fixed to the driven shaft by a fixing member; a drive shaft to which the pulley is fixed and connected to a drive motor; and a drive shaft And a belt stretched over pulleys of a plurality of driven shafts.

The drive device according to claim 5 of the present invention is used for an injection device of an injection molding machine.

In the belt tensioning method for a driving device according to the present invention, a driving shaft connected to a driving motor and a driven shaft for converting rotational motion into linear motion are disposed, and the pulley of the driving shaft and the pulley of the driven shaft are arranged. In the belt tensioning method of the driving device over which the belt is stretched, a pulley having a bearing disposed on the inner peripheral side is rotatably attached to the driven shaft via the bearing, and the pulley and the pulley of the driving shaft are attached. Since the pulley and the driven shaft are fixed by a fixing member in a state where tension is applied to the stretched belt, the pulley shaft of the driven shaft and the shaft core of the driven shaft are prevented from being misaligned, or the movable member of the apparatus Can be prevented from moving in an unfavorable direction, and a good belt tensioning operation can be performed.

A belt tensioning method and a driving device for a driving device according to the present invention will be described with reference to FIGS. FIG. 1 is a side view of an injection device of an injection molding machine that is a drive device used in the belt tensioning method of the drive device of the present embodiment. FIG. 2 is a front view of FIG. 1 viewed from the right side. FIG. 3 is an enlarged sectional view of a portion where the pulley is attached to the driven shaft.

As shown in FIG. 1, an injection device 26 of an injection molding machine, which is a kind of drive device, has a base plate 28 on a bed 27 that can move forward and backward with respect to the bed by a moving mechanism (not shown) of the injection device 26 and can turn. Installed on. A pusher plate 31, which is a movable member, is disposed between a front plate 29 that is a fixed member for the base plate 28 and a rear plate 30. Accordingly, the injection device 26 is of a type called a so-called three-plate system. A heating cylinder 32 is attached to the front plate 29 toward a mold clamping device (not shown). An input port 33 for inputting pellets as a material is provided on the upper surface of the front plate 29, and a hopper 34 is connected to the upper portion of the input port 33. A screw (not shown) is disposed inside the heating cylinder 32. The screw has a shaft portion 35 protruding from the heating cylinder 32. A pulley 36 is fixed to the shaft portion 35, and the rear end of the shaft portion 35 is supported by a thrust bearing (not shown) of the pusher plate 31. A single weighing servo motor 37 is disposed above the pusher plate 31. The pulley 39 attached to the drive shaft 38 of the measuring servo motor 37 and the pulley 36 have a predetermined width and endless timing. A belt 40 is stretched over. Therefore, the screw and its shaft portion 35 are freely rotatable by the measuring servo motor 37.

Further, between the front plate 29 and the rear plate 30, two ball screws 43, 43, which are driven shafts, are pivotally supported by bearings (not shown) that are rotatable and immovable in the axial direction. The pusher plate 31 has the ball nuts 44 and 44 fixed at positions where they are screwed with the ball screws 43 and 43. Therefore, the pusher plate 31 which is a movable member is moved forward and backward by converting the rotational motion of the ball screws 43 and 43 into linear motion of the ball nuts 44 and 44, and at the same time, the screw is also moved forward and backward. The anti-heating cylinder side of the ball screws 43, 43 is a cylindrical shaft portion 45, 45 that protrudes from a portion pivotally supported by the rear plate 30. As shown in FIG. 2, pulleys 46, 46 are detachably fixed to the shaft portions 45, 45, respectively. A single injection servo motor 47 is attached to the side surface of the rear plate 30 with the drive shaft 48 facing the non-heating cylinder. A pulley 49 is fixed to the drive shaft 48. The two driven shafts composed of the ball screws 43 and 43 and the drive shaft 45 are arranged in parallel. A plurality of teeth 49 b are formed on the outer peripheral surface of the outer peripheral ring portion 49 a of the pulley 49. A long hole 51a is formed in the motor mounting portion 50 of the rear plate 30, and a bolt 51b is attached to a mounting bolt hole (not shown) on the injection servo motor 47 side via the long hole 51a, thereby injecting the servo motor. 47 can be fixed. Further, by inserting bolts 52b through a plurality of holes 52a provided in a plate 50a provided in a direction perpendicular to the motor mounting portion 50 and pressing the servo motor 47 for injection in the lateral direction, The position of the drive shaft 48 can be moved. The pulley 49 fixed to the drive shaft 48 and the pulley 46 fixed to the shaft portion 45 of the ball screw 43 are hooked with an endless timing belt 42 having a predetermined width and having teeth 42a formed on the inner surface. Has been passed. The timing belt 42 is tensioned by moving the position of the drive shaft 48.

As shown in FIG. 2, the pulley 46 in this embodiment includes a cylindrical shaft insertion portion 53, a connection portion 54 provided radially from the shaft insertion portion 53, and a large-diameter connected to the connection portion 54. It consists of an outer peripheral ring portion 55. A plurality of teeth 55 b are formed on the outer peripheral surface 55 a of the outer peripheral ring portion 55 in a direction parallel to the inserted shaft portion 45. Further, as shown in FIG. 3, a central hole 56 through which the shaft portion 45 is inserted is formed at the center of the shaft insertion portion 53 in the axial direction. Further, a plurality of bolt holes 58 for attaching a spun ring 57 to be described later are formed on one side 53 a (right side surface in FIG. 3) of the shaft insertion portion 53 around the center hole 56. Further, a bearing 59 is press-fitted to the other side (left side in FIG. 3) of the inner peripheral surface (inner peripheral side) of the center hole 56 in the shaft insertion portion 53 and is fixed from one side by a bearing end cap (not shown). The bearing 59 used in the present embodiment is a low-price single row deep groove ball bearing (radial bearing) including an outer ring 59a, a steel ball 59b, an inner ring 59c, and the like, and an inner ring 59c that can rotate and move via the steel ball 59b. However, the shaft portion 45 of the ball screw 43 can be extrapolated with a slight gap. The type and fixing method of the bearing 59 are not limited to the above. Further, one side of the inner peripheral surface (inner peripheral side) of the center hole 56 of the shaft insertion portion 53 in the pulley 46 is slightly larger than the outer diameter of the shaft portion 45, and the taper member 60 is fixed inside. Has been. The taper member 60 has a tapered surface 60a whose diameter is increased from the inside of the center hole 56 toward the surface 53a on one side.

When the pulley 46 is fixed to the shaft portion 45 of the ball screw 43, the center hole 56 of the pulley 46 is extrapolated to the shaft portion 45, and then a spun ring 57 as a fixing member is inserted and fixed from one side. The spun ring 57 has a center hole 62b into which the shaft portion 45 can be inserted at the shaft center. A large diameter flange portion 61 is formed on one side, and a small diameter portion 62 is formed on the other side. The flange portion 61 is formed with a plurality of bolt holes 61c through which the bolts 64 are inserted from one side surface 61b to the contact surface 61a. The small diameter portion 62 has a tapered surface 62a having a reduced diameter from the contact surface 61a of the flange portion 61 to the end portion 63, and the inner peripheral surface of the center hole 62b is a pressure contact surface. The tapered surface 62 a of the spun ring 57 is slightly steeper than the tapered surface 60 a of the tapered member 60. The shaft portion 45 and the pulley 46 may be fixed by another fixing member instead of the spun ring 57.

Next, a belt tensioning method between the pulley 49 of the drive shaft 48 of the injection device 26 and the pulley 46 of the ball screw 43 as the driven shaft will be described. The belt tensioning operation needs to be performed at the time of new construction of the machine, replacement of the belt, maintenance of the injection servomotor 47, or the like. At the initial stage of this belt tensioning operation, the injection servomotor 47 is temporarily attached by the bolt 51b through the long hole 51a, and the pulley 49 is fixed to the drive shaft 48. Further, the adjustment of the position of the ball nut 44 with respect to the ball screw 43 (parallelism of the pusher plate 31 with respect to the rear plate 30) is also completed, the pusher plate 31 is fixed so as not to move, and the ball screw 43 is also unable to rotate. In the present invention, the belt may be attached while the ball screw that is the driven shaft is rotatable. The reason is that the pulley 46 rotates lightly with respect to the driven shaft, so that the ball screw 43 hardly rotates when the belt is stretched.

Next, the center hole 56 of the pulley 46 for the driven shaft is extrapolated to the shaft portion 45 of the ball screw 43 so that the pulley 49 of the drive shaft 48 and the pulley 46 of the driven shaft are in the same position in the plane parallel to the rear plate 30. Each pulley 46 is positioned. At this time, the pulley 46 for the driven shaft is brought into contact with the shaft portion 45 of the ball screw 43 only through the bearing 59, and the pulley 46 is rotatable with respect to the shaft portion 45.

Next, the timing belt 42 is stretched around the pulleys 46, 46 for the driven shaft and the pulley 49 for the drive shaft so that the teeth of the pulleys 46, 46, 49 and the teeth 42a of the timing belt 42 are engaged with each other. Next, the mounting position of the injection servo motor 47 is adjusted by tightening the bolt 52b, the drive shaft 48 is moved outward in the horizontal direction, and the timing belt 42 is pulled. At that time, the rotation action of the pulleys 46, 46 by the timing belt 42 is substantially the same as the example of FIG. That is, when the timing belt 42 is pulled in the B and C directions, the pulleys 46 and 46 are rotated in the D and E directions, respectively, and tension is applied to the timing belt 42. However, since the ball screw 43 is fixed so as not to rotate as described above, the pulley 46 smoothly rotates with respect to the shaft portion 45 via the bearing 59. Further, the radial load does not concentrate only between the pulley and the driven shaft as in the case where the pulley is fixed to the driven shaft. As a result, even if the timing belt 42 is stretched, the core of the pulley 46 with respect to the shaft portion 45 is maintained. When a predetermined tension is applied to the timing belt 42, the bolt 51b is tightened into the elongated hole 51a and a mounting bolt hole (not shown), and the injection servo motor 47 is completely fixed to the rear plate 30. A belt 42 is stretched.

Next, the pulley 46 is fixed to the shaft portion 45 of each ball screw 43. As shown in FIG. 3, the spun ring 57 as a fixing member is fitted to the shaft portion 45, and the taper surface 60 a of the taper member 60 fixed to the inner peripheral side of the pulley 46 is tapered. Insert until the surface 62a contacts. Next, the bolts 64 are respectively inserted into the bolt holes 61c of the flange portion 61 until the one side surface 53a of the pulley 46 and the contact surface 61a of the flange portion 61 are pressed against each other and the tapered surfaces 60a and 62a are pressed against each other. Tighten each bolt 64. At this time, the small diameter portion 62 of the spun ring 57 is pressed toward the shaft portion 45 by the pressure contact between the tapered surfaces 60a and 62a, and the pressure contact surface of the center hole 62b is strongly brought into contact with the outer peripheral surface of the shaft portion 45. Is fixed to the shaft portion 45 and completely fixed. Then, the pusher plate 31 can be moved and the ball screw 43 can be rotated to complete the belt tensioning operation of the driving device.

Although the present invention is not enumerated one by one, it is not limited to that of the above-described embodiment, and it goes without saying that the present invention is applied to those modified by a person skilled in the art based on the gist of the present invention. is there. Although the three-plate type injection device 26 has been described in the present embodiment, it may be used for a two-plate type injection device including a front plate and a pusher plate. In that case, a ball screw that is a driven shaft relative to the ball nut may move in the axial direction. Further, the driven shaft may be a ball nut, a pulley may be attached to the ball nut, and the ball screw may be moved by the rotation of the ball nut. Further, the driven shaft may be a feed screw or other rotational shaft as long as it is a shaft that transmits the rotational force of the drive shaft to another. Furthermore, the number of drive shafts and the number of driven shafts are not limited as long as they are at least one. Further, the shaft or member for pulling the belt may be an idling roller or another member instead of the drive shaft.

Further, the drive device is not limited to the injection device 26 of the injection molding machine, but may be a mold clamping device, an ejector device, a take-out machine, or the like. Further, in the case of an injection molding machine, all types such as for metal working, injection compression molding machine, vertical injection molding machine, plunger type molding machine and the like are possible. In addition to injection molding machines, the present invention can also be applied to various industrial machines such as presses and machine tools for metal processing, and other mobile machines.

It is a side view of the injection device of the injection molding machine which is a drive device used for the belt tensioning method of the drive device of this embodiment. It is the front view which looked at FIG. 1 from the right direction. It is an expanded sectional view of the part where a pulley is attached to a driven shaft. It is explanatory drawing of the conventional method. It is explanatory drawing of the conventional method. It is explanatory drawing of another conventional method.

Explanation of symbols

26 Injection device 30 Rear plate 31 Pusher plate 36, 39, 46, 49 Pulley 40, 42 Timing belt 43 Ball screw 45 Shaft portion 38, 48 Drive shaft 47 Servo motor for injection 57 Span ring 59 Bearing

Claims (5)

In the belt tensioning method of the drive device in which a drive shaft connected to the drive motor and a driven shaft are disposed, and a belt is stretched between the pulley of the drive shaft and the pulley of the driven shaft.
A pulley provided with a bearing on the inner peripheral side is rotatably attached to the driven shaft via the bearing,
In a state where tension is applied to the belt spanned between the pulley and the pulley of the drive shaft,
A belt tensioning method for a driving device, wherein the pulley and the driven shaft are fixed by a fixing member. A pulley with a bearing on the inner circumference is attached to each of the driven shafts,
2. The drive according to claim 1, wherein the pulley and the driven shaft are fixed by a fixing member in a state in which tension is applied to a belt that spans the pulleys of the plurality of driven shafts and the pulley of the drive shaft. How to stretch the belt of the device. 3. The belt tensioning method for a driving device according to claim 1, wherein the driving device is used in an injection device of an injection molding machine. A plurality of driven shafts that convert rotational motion into linear motion;
Before the fixed bearing is provided with the bearing facing the driven shaft on the inner peripheral side, the driven member is rotatably provided with respect to the driven shaft, and then the driven member is driven by the fixing member in a state in which tension is applied to the belt that is passed around. A pulley fixed to the shaft;
A drive shaft having a pulley fixed and connected to a drive motor;
A drive device comprising: a pulley spanned between the drive shaft pulley and the plurality of driven shaft pulleys. The drive device according to claim 4, wherein the drive device is used in an injection device of an injection molding machine.

Images