JPS6227291B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propulsive force imparting device that utilizes spring torque.

This type of device is used, for example, in a chain tensioner, where the object is intended to move with a certain force in one direction, but requires properties similar to those of a rigid body in the opposite direction. In other words, a chain tensioner applies a certain tension to the chain by pressing it in one direction when the chain becomes loose due to elongation or wear during use. In the opposite direction (reaction force), characteristics close to those of a rigid body are desirable.

Conventionally, for example, in the case of chain tensioners, there are two types: one that manually adjusts the chain according to its elongation, and the other that automatically adjusts the elongation.The former is relatively inexpensive, but maintenance is troublesome. However, the latter has drawbacks such as the tendency to generate abnormal noise, and the latter has the drawback that the entire device is complicated and expensive because it uses hydraulic power.

The present invention was made in view of the above circumstances, and can properly secure propulsion force with an extremely simple mechanism, has characteristics similar to a rigid body in response to reaction force, and does not require maintenance. The present invention aims to provide a novel propulsion imparting device that utilizes spring torque.

The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is a plan view of a propulsive force imparting device according to the present invention, and FIG. 2 is a sectional view taken along the line -- in FIG.

Reference numeral 1 denotes a support base having a bearing portion 1a in the center. Reference numeral 2 denotes a cylindrical case with a substantially H-shaped cross section, the interior of which is partitioned into a cavity A on the upper side and a spring housing section B on the lower side by a horizontal partition plate 3 having a bearing portion 3a. Reference numeral 4 denotes a first shaft, which is composed of a head 5 having a substantially U-shaped cross section and a shaft portion 6 that hangs outward from the center of the bottom 5c of the head 5. A portion 5a is engraved. Reference numeral 7 denotes a second shaft consisting of a square rod part 7a and a male threaded part 7b which is screwed into the female threaded part of the first shaft. 8 is a bearing plate, and a bearing part 8a corresponding to the cross-sectional shape of the square rod part 7a of the second shaft is formed in the center thereof. 9 is a mainspring.

Then, the cylindrical case 2 is installed upright on the support stand 1, and the first shaft 4 has its shaft portion 6 connected to the bearing portion 3.
a, 1a, and is rotatably placed in the case 2 with the open end outer periphery 5b and bottom 5c of the head 5 in sliding contact with the inner peripheral surface of the case 2 and the partition plate 3, respectively. A snap spring 10 is attached to the insertion end of the shaft portion 6, and its sliding in the axial direction is restrained. The second shaft 7 has its male threaded portion 7b connected to the female threaded portion 5a of the first shaft 4.
The square rod portion 7a is inserted into the bearing portion 8a of the bearing portion 8, and rotation is restrained and the rod portion 7a is slidably mounted in the axial direction. The mainspring spring 9 has its inner end fixed to the groove 6a of the first shaft,
The outer end thereof is fixed to an appropriate location of the case 2 and is installed in the spring storage part B within the case 2.

Furthermore, reference numeral 11 denotes a knob having one end inserted into and removably inserted and latched into the shaft end split groove of the first shaft passing through the support 1, and the other end appropriately latched to the leg of the support 1. When the knob 11 is in such a linked state, the rotation of the first shaft 4 is locked, and the lock is released by releasing both or one of the latches of the knob 11. is configured to release the .

Further, in the above embodiment, the first shaft had a female threaded portion and the second shaft had a male threaded portion, but in other words, the first shaft had a male threaded portion and the second shaft had a female threaded portion. Of course, it is good to do so.

In the above configuration, when the knob 11 is forcibly rotated in the direction of tightening the mainspring spring 9, the first shaft 4 rotates while tightening the mainspring spring 9. The rotation of this first shaft 4 is caused by the threaded portion 5a,
7b, the movement is converted into a propulsion motion of the second shaft in either the direction of arrow a or the direction of arrow b. The propulsion movement of the second shaft 7 is determined by the threaded portions 5a and 7b.
Determined by whether the screw is left-handed or right-handed. When the forced rotational force applied to the knob 11 is released, the first shaft 4 rotates in the opposite direction to the forced rotation due to the action of the spring torque of the mainspring spring 9, and along with this rotation, the second shaft 7 It also has a propulsion movement in the opposite direction to that described above.

If a reaction force that exceeds the propulsive force acts on the second shaft 7 during the propulsion movement of the second shaft 7, the propulsion movement will immediately stop, but no matter how great the reaction force is, The second shaft 7 does not move in the direction of the reaction force even if because,
Since the reaction force acts only in the axial direction of the second shaft 7, it is impossible for the second shaft 7 to move in the reaction force direction beyond the threaded portions 5a and 7b.
This is because it has characteristics close to that of a rigid body in the direction of reaction force. If the reaction force is even slightly lower than the propulsive force of the second shaft 7, the spring torque of the mainspring spring 9 is always acting on the first shaft 4, so the second shaft 7 immediately starts propulsion in the same direction. Start exercising.

The above-mentioned propulsion force imparting device is used, for example, as a chain tensioner shown in FIG.

In FIG. 3, numerals 34 and 35 are gears, and a chain 30 is stretched around these gears 34 and 35 in a loop shape. Reference numeral 32 designates a shoe which is pivotally supported at one end and is disposed so as to contact the chain 30 from the outside.

The propulsive force imparting device is connected to the second shaft 7.
The tip of the shoe 32 is brought into contact with the upper surface of the shoe 32, and the supporting base leg is fixed to the fixed wall 31 with bolts 36. At this time, the mainspring spring 9 is in a tightly wound state. In this state, when the knob 11 is released from the locked state, the first shaft 4 rotates due to the initial torque of the mainspring spring 9, and is directed to the second shaft 7 in a certain direction (direction a) via the threaded part.
The driving force is given.

Therefore, when the chain 30 is stretched or loosened, the second shaft 7 advances in the direction a due to the torque action of the mainspring spring 9, and immediately puts the chain 30 in a tensioned state without loosening through the shoe 32. maintain. (See the broken line in Figure 3).

Note that when a constant torque spring is used as the mainspring spring 9, it goes without saying that the propulsive force applied to the second shaft can always be constant.

As described above, according to the propulsion force imparting device according to the present invention, despite the extremely simple structure that utilizes spring torque, it is possible to adequately secure propulsion force, and moreover, it is possible to properly secure propulsion force, and moreover, it is possible to suppress reaction force. It has characteristics close to that of a rigid body, and since the spring torque is always acting on it, a certain amount of propulsion force can always be applied to the object, so maintenance is unnecessary and it can be used in belt tensions, etc. If you do, the effect will be significant.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment according to the present invention, FIG. 2 is a sectional view taken along the line -- in FIG. DESCRIPTION OF SYMBOLS 1... Support stand, 2... Cylindrical case, 4... First shaft, 7... Second shaft, 9... Mainspring spring.

Claims (1)

[Claims] 1. A male threaded portion is provided at one end of the first shaft or the second shaft, and a female threaded portion is provided at the other end, and is opposite to the threaded portion forming side of the second shaft. The first shaft is formed into a columnar part having a non-circular cross section, the two threaded parts are screwed together to connect the two shafts, and the first shaft is restrained from sliding in the axial direction by a bearing so that it can rotate freely. Attach the second
The columnar part of the first shaft is inserted into another bearing formed in a shape corresponding to the cross-sectional shape of the first shaft, and the rotation is restrained and the shaft is slidably slidable in the axial direction of the first shaft. A propulsive force imparting device characterized in that a propulsive force in a fixed direction is imparted to the second shaft via both of the threaded portions by applying torque. 2. The inner end is fixed to the first shaft, the outer end is fixed to an appropriate fixing member, a mainspring is attached, the shaft is forcibly rotated in the winding direction of the mainspring spring, and the forced rotation is released. 2. The propulsion force imparting device according to claim 1, wherein the spring applies a spring torque in a constant rotational direction to the shaft.