JPS61248950A - Propulsion exerting device - Google Patents

Abstract

PURPOSE:To increase a propulsion without an increase in the scale of a device, according to the method wherein, in addition to a twist spring, an auxiliary spring, directly energizing a press body in a ptopulsive direction, is mounted to a propulsion exerting device exerting tension on a chain for car engine. CONSTITUTION:A device comprises a casing 20, having a cavity part 21 formed in the direction of an axia; a rotary shaft 30, inserted in the cavity part 25; a press body 40, threadedly joined with the forward end part of the rotary shaft 30; a stopper 50; a seal bolt 60; and a twist spring 70 serving to rotate the rotary shaft 30. The press body 40 is inserted in the cavity part 21 in the casing 20 in a state in that it is threadedly joined with a small part 32 of the rotary shaft 30, and a portion threadedly joined with the rotary shaft 30 is supported to a bearing 80. An auxiliary spring 100 is attached between a cap 85 and the forward end surface of the casing 20. The auxiliary spring 100 is inserted externally of the press body 40 in a compressed condition, and its restoring force causes the cap 85 to be energized in a propulsive direction, i.e., the direction of the axis of the press body 40.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a propulsion force applying device that applies a constant tension to a chain or timing belt that drives a camshaft of an engine of a two-wheeled vehicle or a four-wheeled vehicle. It is something.

<Prior art> The propulsion force applying device is used, for example, as a chain tensioner or belt tensioner, and when the chain or belt becomes loose due to stretching or wear during use, it pushes the chain or belt in a certain direction. Although the tension is maintained at a constant level, the pressing force acts in a manner similar to that of a rigid body in response to a reaction force in the opposite direction.

FIGS. 6 and 7 show each side of a conventional propulsion applying device.

The propulsion force imparting device shown in FIG. 6 includes a casing 3 consisting of a cylindrical portion 1 in which an axial cavity 1a is formed and a flange portion 2 that is orthogonally connected to the base (right end portion) of the cylindrical portion 1; A disk-shaped rotating body 4 is attached so as to come into contact with a step in the cavity la of the casing 3, and the rotating body 4 is screwed onto the rotating body 4 and slides in the axial direction of the cylindrical part 1 by the rotation of the rotating body 4. It consists of a shaft 5 and a tear spring 6 which is fitted onto the shaft 5 and rotates the rotating body 4. The flange portion 2 of the casing 3 is attached to equipment such as an engine (not shown) with bolts or the like, and has a mounting hole 2a through which the bolt is inserted. The cylindrical portion 1 to which the flange portion 2 is connected is inserted into the inside of a device.

The shaft 5 presses the end of the shaft 5 against the chain or belt of the attached member to apply a certain tension to them. By passing through the preventing body 7, the rotational motion of the rotary body 4 is converted into a sliding motion in the axial direction of the casing 3, and the preventive body 7 is advanced from the inside of the casing 3. Rotating body 4
The rotation is performed by a torsion spring 6 which is fitted onto the shaft 5, and one end 6a of the torsion spring 6 is engaged with a rotation prevention body 7, and the other end 6b is engaged with the rotating body 4. This torsion spring 6 is assembled in the casing in a state in which it is twisted in advance and given a predetermined torque, and the rotating body is rotated by its restoring force. Further, numeral 8 in the figure is a stopper screw that locks the sliding movement of the shaft 5, and is screwed into a screw hole 5a formed in the base end surface of the shaft 5 from the flange portion 2 side. Therefore, after installing this device into a device, the lock is released by removing the stopper screw 8 and the shaft 5
advances from the chain line state to the solid line state, and a predetermined pressing force can be applied to the chain or belt. Note that after the stopper screw 8 is removed, a rubber cap 9 is fitted in place of the stopper screw 8 to prevent dust, water, etc. from entering the casing.

In the conventional device shown in FIG. 7, the cylindrical body 1 is attached to the base end side of the rotating body 4 inserted into the cylindrical portion 1 of the casing 3 by welding, screws, etc.
0 is integrally attached, and a stopper 11 that engages with the cylindrical body 10 is inserted from the proximal end side of the casing 3. That is, this stopper 11 is inserted into a slit 12 formed in the cylindrical body 10 and a slit 13 formed in the casing 3, and the rotation integrally with the cylindrical body 10 is locked by insertion of this stopper 11. .

Therefore, if the plate-shaped stopper 11 is pulled out after attaching this propulsive force imparting device to a predetermined device such as an engine,
When the lock is released, it becomes possible to constantly apply tension to the chain, etc. inside the engine.

<Problems to be Solved by the Invention> However, since the propulsive force of any of the above conventional devices is small, they work effectively as a tensioner for a chain with a small amount of elongation, but they cannot be used as a tension thinner for a belt with a large elongation I. It cannot be made to act as an effective tensile thinner. In order to increase this propulsive force, it is necessary to make the torsion spring stronger, which requires a larger space for installing the torsion spring, resulting in an increase in the size of the entire device.

Means for Solving the Problems> The present invention has been made to solve the above problems, and provides a propulsive force imparting device that increases the propulsive force without increasing the size of the device.

For this reason, the propulsion force applying device according to the present invention is characterized in that an auxiliary spring is provided separately in addition to the torsion spring.

Function> In the present invention, the auxiliary spring acts to expand in the propulsion direction and increase the propulsive force.

<Example> Hereinafter, an example of the propulsive force applying device according to the present invention will be specifically described with reference to FIGS. 1 to 4.

In these figures, the propulsion force applying device includes a casing 2o in which a cavity 21 is formed in the axial direction, a rotating shaft 30 inserted into the cavity 21 of the casing, and a cylinder screwed into the tip of the rotating shaft 30. The casing 20 includes a pressing body 40 having a shape, a stopper 50 and a seal bolt 6o attached to the base end (left end in the illustrated embodiment) of the casing 20, and a torsion spring 70 for rotating the rotating shaft.

The casing 20 consists of a horizontally elongated cylindrical portion 22 and a flange portion 23 that is orthogonally connected to the base side of the cylindrical portion 22. Mounting holes 24 are provided at the top and bottom of the flange portion 23 to attach equipment such as an engine (not shown). ) is fixed to the outside wall of the building with bolts. In this installation, the cylindrical portion 22 is located inside the device and the flange portion 23 is located outside the device.

Both the tip (right end in FIG. 1) and base (left end in FIG. 1) of the cylindrical portion 22 of the casing 20 are open, and the rotary shaft 30
．． A pressing body 40 and a torsion spring 70 are inserted, while a stopper 50 and a seal bolt 60 are attached from the base end side.

The rotating shaft 30 consists of a large diameter part 31 and a small diameter part 32, a torsion spring 70 is fitted onto the large diameter part 31, and a torsion spring 70 is inserted into the large diameter part 31.
A pressing body 40 is screwed onto 2.

Here, the screw engagement with the pressing body 40 is achieved by carving a male threaded portion 33 on the outer peripheral surface of the small diameter portion 32 and forming a male threaded portion 41 on the inner peripheral surface of the pressing body 40. Also, large diameter part 3
One end 71 of the torsion spring 70 inserted into the casing 20 is inserted into the engagement hole 25 formed in the casing 20, and the other end 72 is inserted into the engagement hole 33 formed in the base end of the large diameter portion 31. It has been inserted. Therefore, when assembled with the torsion spring 70 twisted to apply a predetermined torque, the rotating shaft 30 will rotate due to the restoring force of the torsion spring 70, resulting in 1).

The pressing body 40 is inserted into the cavity 21 of the casing 20 while being screwed onto the small diameter portion 32 of the rotating shaft 30, and the screwed portion with the rotating shaft 30 is supported by a bearing 80. That is, this bearing 80 is attached to the tip of the cylindrical portion 22 of the casing 20 and is
As shown in FIG. The outer periphery of the sliding hole 81 is formed in the same shape as the sliding hole 81.
The pressing body 40 is inserted into the inside of the press body, so that even when the rotating shaft 30 rotates, the pressing body 40 does not rotate but slides.

To install the bearing 80, a claw 82 protrudes from the outer surface of the bearing 80, and a notch 26 into which the claw 82 is inserted is formed at the tip of the casing 20. This is done by rotating the bearing 80 so as to abut against the tip end surface and inserting the pawl 82 into the notch 26. A circumferential groove is formed on the outer periphery of the tip of the casing 20,
After the bearing 80 is inserted, a circlip 83 is wrapped around this circumferential groove to prevent the bearing 80 from being pulled out.

Next, the stopper 50 attached to the base side of the casing 20 consists of an elongated engagement piece 51 and an operation piece 52 connected to the engagement piece 51, as shown in FIG.
1 is inserted into the engagement groove 33 of the rotary shaft 30 and has a wooden shape.

On the other hand, the operation piece 52 is inserted into the proximal end of the casing 20 so as to maintain an engaged state with the casing 20. That is, as shown in FIG. 2, a cross-shaped stopper groove 27 is formed in the base end surface of the casing 20, and the operation piece 52 is inserted into this stopper 1l127. Thus, the stopper 50 locks the rotary shaft 30 so that it does not rotate. Further, the torsion spring 70 is unwound by pulling out the operation piece 52 of the stopper 50 from the stopper groove 27 and rotating the operation piece 52 with the engagement piece 51 inserted into the engagement groove 33. The seal bolt 60 is screwed into the proximal end of the casing 20 to seal the cavity 21 of the casing 20 to prevent dust, water, etc. from entering. Therefore, the seal bolt 60 is formed with a flange 61 that covers the base end of the opened casing, and
The proximal end of the casing 20 is screwed into the base end of the casing 20 through the O-ring 62. In FIG. I started doing it.

In this embodiment, the pressing body 40 slides in the axial direction inside the casing 20 to press the chain inside the device and apply a constant tension to the chain.

Here, the tip of the pressing body 40 is covered with a cap 85 that comes into contact with a chain or the like. This cap 8
5 is made of an elastic body such as rubber, and is fixed to the tip of the pressing body 40 by a spring pin 86ζ inserted in a direction perpendicular to the pressing body 40;
An auxiliary spring 100 made of a compression spring is attached between the front i-side of the casing 5 and the i-plane of the casing 20. This auxiliary spring 1
00 is fitted onto the pressing body 40 in a compressed state, and its restoring force urges the cap 85 in the propulsion direction, that is, in the axial direction of the pressing body 40. Therefore, in addition to the restoring force of the torsion spring 70, the restoring force of the auxiliary spring 100 acts on the pressing body 40, and the propulsive force of the pressing body 40 is increased, which is effective even for belts with a large amount of elongation. can be made to act.

FIG. 5 is a cross-sectional view of another embodiment of the invention, in which the same elements as in the above embodiment are designated by the same reference numerals. In this embodiment, a conical spring is used as the auxiliary spring 100, and the distal end surface of the casing 20, which the large diameter portion of the conical spring 100 contacts, forms a large diameter flange portion 28. Also in this embodiment, the propulsive force of the pressing body 40 is increased by attaching the conical spring 100 in a compressed state.

Note that the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, a main spring may be used instead of a torsion spring by rotating a rotating shaft, or a plurality of auxiliary springs may be used. You may use plate 1f. Alternatively, instead of attaching a cap to the pressing body, a large-diameter flange may be integrally formed at the tip of the pressing body, and an auxiliary spring may be provided between the flange and the casing.

<Effects of the Invention> As described above, according to the present invention, in addition to the spring that rotates the rotary shaft and propels the pressing body, an auxiliary spring that directly biases the pressing body in the propulsion direction is provided, so that the propulsive force is reduced. This makes it possible to provide a propulsion force imparting device that is optimal as a tensioner for a belt with a large amount of elongation.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is a left side view thereof, FIG. 3 is a sectional view taken along line I-II in FIG. 1, FIG. 4 is a perspective view of a stopper, and FIG. The figure is a longitudinal sectional view of another embodiment of the present invention, FIG. 6 is a left side view and a longitudinal sectional view of a conventional example, and FIG. 7 is a left side view, a longitudinal sectional view, and a right side view of another conventional example. be. 20...Casing, 30 Rotating shaft, 40 Pressing body, 50 Stopper,

Claims (3)

[Claims] (1) A rotating shaft and a pressing body are inserted into the casing in a screwed state, and a spring is provided to rotate the rotating shaft, and the rotational force of the rotating shaft is used as a propulsive force in the axial direction of the pressing body. A propulsion force imparting device, characterized in that an auxiliary spring is provided that biases the pressing body in a propulsion direction. (2) Claim No. 1 in which the auxiliary spring is a coil spring (
1) The propulsion force imparting device described in section 1). (3) Claim No. 1 in which the auxiliary spring is a conical spring
) The propulsion force imparting device described in item 2.