JPH10267062A - Tension adjusting device for coil spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of tension adjusting of a coil spring without using a screw shaft with a changeable protruding length to outside a casing and a special nut by simple operation, simple in structure and easily assembled and manufactured at a reduced cost. SOLUTION: To a casing 1 receiving a pressed unit 2 and a coil spring 3, an operating shaft 4 having a helical groove 6 corresponding to a spiral of the coil spring 3 in a peripheral surface is mounted so as to be rotatable in a peripheral direction and not to be movable in an axial direction, one end side 3b without throwaway winding part of the coil spring 3 pressing another end side 3a into press contact with the pressed unit 2 is screwed to the helical groove 6 of the operating shaft 4, a turn lock means of the coil spring 3 is provided, and according to a change of screwing depth of the operating shaft 4 and the coil spring 3 due to rotational operation of the operating shaft 4, spring tensions relating to the pressed unit 2 is changed to be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a pressing portion of a valve body and a valve rod, a pressing portion of a cam follower, a piston pressing portion of a cylinder with a built-in spring, a spring pressing lever, a writing implement using ink, and a paint in various valves. The present invention relates to a device that adjusts the spring pressure of a coil spring in a portion that utilizes the elastic force of a coil spring in a compressed state, such as a pressurizing section of a variable-volume liquid tank of a coating tool.

[0002]

2. Description of the Related Art Conventionally, the following two methods are generally employed for adjusting the spring pressure of a coil spring used in a compressed state. One of them is, as shown in FIG. 6 (A), a screw shaft 23 mounted on a casing 20 containing a pressed body 21 and a coil spring 22 abutting on one end thereof.
Is screwed coaxially with the coil spring 22, the tip end 22 a of the screw shaft 23 is pressed against the other end of the coil spring 22, and the compression of the coil spring 22 is performed by the axial movement accompanying the rotation of the screw shaft 23. This is a method of changing the degree. 6B, the screw shaft 24 is rotatably and axially immovably held by the casing 20 containing the pressed body 21 and the coil spring 22 in the same manner as shown in FIG. The nut 25 screwed to the screw shaft 24 is made non-rotatable and axially movable by uneven engagement with a linear guide such as an axial groove 20 a provided on the inner surface of the casing 20. This is a method in which the degree of compression of the coil spring 22 is changed by pressing against the other end and moving the nut 25 in the axial direction as the screw shaft 24 rotates.

[0003]

However, in the former means shown in FIG. 6A, the length of the screw shaft 23 protruding outside the casing 20 changes with the adjustment of the spring pressure. Depending on the type of the product and the structure of the assembly site, it is difficult to secure a space allowing the change in the protruding length, or the protruding portion of the screw shaft 23 deteriorates the operability when using the product, There are problems such as a reduction in commercial value in appearance due to the protruding portions. On the other hand, in the latter means of FIG. 6B, since the nut 25 is used, the number of members is increased as compared with the former, and the nut 25 itself is expensive in a special form, so that the member cost is high, and Coil spring 22
There is a problem that it takes time to assemble and manufacture depending on the structure of the assembling part.

In view of the above-mentioned circumstances, the present invention employs a completely new mechanism as a spring pressure adjusting device for a coil spring. It is an object of the present invention to provide a spring which can perform reliable spring pressure adjustment by a simple operation without using a nut, and which can be assembled and manufactured very easily at a low cost.

[0005]

To achieve the above object, a spring pressure adjusting device for a coil spring according to a first aspect of the present invention includes a casing for accommodating a body to be pressed and a coil spring for pressing the body. An operating shaft having a spiral groove corresponding to the spiral of the coil spring on the peripheral surface is mounted so as to be rotatable in the circumferential direction and immovable in the axial direction, and one end of the operating shaft is pressed against the pressed body. The other end side is screwed into the spiral groove of the operation shaft, and is provided with a detent means for the coil spring. By changing the screwing depth of the operation shaft and the coil spring due to the rotation operation of the operation shaft, It is configured such that the spring pressure on the pressed body changes in strength.

In this case, the coil spring used is
At least one end is a discarded winding portion, that is, a form in which windings for several turns of the end portion are wound in close contact and do not participate in the expansion and contraction operation, and do not have the discarded winding portion. The screw is screwed into the spiral groove of the operating shaft from the side, and the end on the opposite side is pressed against the pressed body and is not rotated by the rotation preventing means. The screwing depth with the operation shaft changes. The pressing force (spring pressure) on the pressed body is determined by the helical density (degree of compression) of the coil spring existing between the position of contact with the pressed body and the position of the distal end of the operation shaft.

Therefore, if the rotation direction of the operating shaft is a direction in which the screwing depth is reduced, the coil spring has a winding circumference corresponding to the rotation amount of the operating shaft (for example, three rotations for three rotations). Since the helical density is pushed out from the tip of the operating shaft and the helical density increases accordingly, the spring pressure increases. On the other hand, if the rotation direction is a direction in which the screwing depth is reduced, the coil spring is wound around the operation shaft by the amount corresponding to the rotation amount of the operation shaft, and the spiral density becomes coarser accordingly. Thus, the spring pressure will decrease. In addition,
The end of the coil spring that presses against the pressed body may have a discarded winding part.

According to a second aspect of the present invention, in the spring pressure adjusting device for a coil spring according to the first aspect of the present invention, the rotation preventing means for the coil spring is provided so that the one end side of the coil spring and the pressed body cannot rotate relative to each other. It depends on the situation. This detent means is effective when the pressed body does not have a rotating property, and it is the simplest in configuration since it is only necessary to engage one end of the coil spring with the pressed body.

According to a third aspect of the present invention, in the spring pressure adjusting device for a coil spring according to the first aspect, the rotation preventing means of the coil spring is formed by a linear guide groove formed in a peripheral wall of a casing surrounding the coil spring and extending along an axial direction. The wire end of the coil spring bent outward in the radial direction is fitted into the coil spring. In this case, the wire end of the coil spring to be fitted into the linear guide groove may be set on either side of both ends of the coil spring,
Since the wire end can be displaced in the axial direction within the range of the linear guide groove, the axial movement of the coil spring accompanying the adjustment of the spring pressure, and the axial displacement of the pressed body do not interfere, and A reliable rotation stop can be performed regardless of the presence or absence of rotation.

According to a fourth aspect of the present invention, in the spring pressure adjusting device for a coil spring according to any one of the first to third aspects, the operating shaft is provided with a shaft portion having a spiral groove on a peripheral surface and a twisted portion disposed outside the casing. And a head portion for use. Therefore, when adjusting the spring pressure, the operation shaft can be easily rotated by pinching the torsion head with a finger.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spring pressure adjusting device for a coil spring according to the present invention will be specifically described below with reference to the drawings.

In the spring pressure adjusting device of the first embodiment shown in FIGS. 1 and 2, a pressed body 2 and a coil spring 3 for pressing the same are placed inside a cylindrical casing 1.
Is accommodated, and the open end 1a of the casing 1
The operation shaft 4 is fitted. The coil spring 3 has a discarded winding part on one end 3a,
b is a shape in which the spring spiral is interrupted as it is.

Although not shown in detail, the pressed body 2 constitutes a valve rod, a cam follower, a variable-volume liquid tank, and the like. Is held in the casing 1 in a non-rotatable state. At the end of the pressed body 2, a spring receiving portion 2b concentric with the main body portion 2b and having a small diameter and having a round shaft shape is projected, and a radial locking hole 5a is provided at the base of the spring receiving portion 2b. doing.

The operating shaft 4 is disposed within the casing 1 and has a screw shaft portion 4a having a spiral groove 6 on the outer peripheral surface thereof at a pitch corresponding to the spiral of the coil spring 2 in the natural state.
A torsion head 4b arranged outside the casing 1 and having a number of axially extending ridges 7 on the outer peripheral surface;
c, the outer flange portion 41 of the holding shaft portion 4c is engaged with the opening edge of the casing 1, and the inner flange portion 42 of the holding shaft portion 4c is provided on the inner periphery of the casing 1. By engaging with the convex portion 11, the casing 1 is held rotatably and immovable in the axial direction.

The coil spring 3 has one end 3a having a discarded winding portion fitted outside the spring receiving portion 2b of the pressed body 2 and pressed against the pressed body 2 and radially inward of the one end 3a. The bent line end 31 is engaged with the locking hole 5 of the spring receiving portion 2b.
a, the other end 3b of the operation shaft 4 is screwed into the spiral groove 6 of the screw shaft 4a.

In the above configuration, when the torsion head 4b of the operation shaft 4 is picked and turned with a finger, the coil spring 3 is prevented from rotating, and thus the screw shaft portion 4 is guided by helical guidance.
The screwing depth of the coil spring 3 with respect to a changes. The pressing force (spring pressure) of the coil spring 3 against the pressed body 2 is the density of the spring spiral existing between the contact position with the pressed body 2 and the tip end position of the screw shaft portion 4a, that is, compression. Since it is determined by the degree, the strength can be easily and steplessly adjusted only by rotating the operation shaft 4.

For example, if the operating shaft 4 is rotated from the state shown in FIG.
The coil spring 3 screwed around the winding shaft corresponds to the rotation amount of the operation shaft 4 (for example, three rotations for three rotations).
1B, the spiral density is increased as shown in FIG. 1B, and the pressing force against the pressed body 2 is increased accordingly. On the other hand, for example, FIG.
If the operation shaft 4 is rotated in the direction opposite to the above from the state of (B), the coil spring 3 is wound around the screw shaft portion 4a by the number of turns corresponding to the amount of rotation, and the helical density is reduced. As a result, the pressing force against the pressed body 2 decreases.

The means for preventing the rotation of the coil spring 3 includes the locking hole 5a and the wire end 3 as in the first embodiment.
Various configurations can be adopted without being limited to the engagement with the first. For example, when the pressed body 2 is non-rotatable as in the first embodiment, the spring receiving portion 2b may have a notched circular cross section as in the second embodiment shown in FIG. The coil spring 3 may have a non-circular cross section such as a square shape as in the third embodiment shown in FIG. Also, as in the fourth embodiment shown in FIG. 4, an axial locking hole 5b is provided in an annular stepped portion 2c between the main body 2a of the pressed body 2 and the spring receiving portion 2b. The wire end 32 bent in the axial direction of the coil spring 3 can be inserted into the coil spring 3 to prevent rotation.

Further, the rotation of the coil spring 3 can be stopped on the casing 1 side. For example, in the fifth embodiment shown in FIG. 5, a linear guide groove 8 extending in the axial direction provided on the inner peripheral surface of the casing 1 surrounding the screw shaft portion 4a of the operating shaft 4 is bent outward in the radial direction of the coil spring 3. When the operating shaft 4 is rotated, the coil spring 3 does not rotate and the bent wire end 33 is fitted.
The screwing depth of the screw shaft portion 4a with the screw shaft portion 4a is changed with the movement of the screw 3 in the linear guide groove 8. In this case, the coil spring 3 need only be pressed against the pressed body (not shown) in a disengaged state, so that the pressed body may be rotatable in the circumferential direction.

In the fifth embodiment, the linear guide groove 8 of the casing 1 is provided at a position opposed to the screw shaft portion 4a. A configuration in which the wire end of the coil spring on the pressed body side is fitted into the linear guide groove can also be adopted. Further, these linear guide grooves may be formed in a slit shape communicating between the inside and outside of the casing 1.

In the above-described embodiment, the coil spring 3 having a discarded winding portion at one end which is in contact with the pressed body 2 is illustrated. However, in the present invention, a coil spring having both ends without discarded winding portions can be used. It is. The operating shaft 4 is not limited to the one having the torsion head 4b as in the embodiment, but may be configured to rotate indirectly via a gear or the like. Can also be automated. In addition, in the present invention, only the shape of the casing 1, the type and shape of the pressed body 2, the length of the screw shaft portion 4 a in the operation shaft 4, the pitch and depth of the spiral groove 6, and the rotation of the operation shaft 4 to the casing 1. The detailed configuration, such as the structure for freely holding, can be variously modified in addition to the embodiment.

The spring pressure adjusting device of the present invention includes, for example, a pressing portion of a valve body and a valve rod by a coil spring, a pressing portion of a cam follower by a coil spring, in various valves such as an on-off valve, a check valve, and a safety valve. A piston pressing part of a cylinder with a built-in spring, various levers that are elastically urged in one direction by a coil spring, a pressurizing part by a coil spring of a variable volume liquid tank built in a writing instrument using ink or a paint applicator, etc. The present invention can be applied to various parts using the elastic force of a coil spring in a compressed state.

[0023]

According to the first aspect of the present invention, as a spring pressure adjusting device for a coil spring, a conventional screw shaft or a special nut whose projection length changes outside the casing is not used, and a simple spring is used. An object is provided which can perform reliable spring pressure adjustment by operation, and which is extremely simple in structure and can be assembled and manufactured at low cost.

According to the second aspect of the present invention, in the above-described spring pressure adjusting device for a coil spring, particularly when the pressed body that presses and contacts the coil spring has no rotation, the spring pressure is adjusted. There is an advantage that the required rotation of the coil spring can be prevented by a very simple configuration.

According to the third aspect of the present invention, in the above-described spring pressure adjusting device for a coil spring, the coil spring can be reliably stopped from rotating regardless of the rotational property of the pressed body that presses the coil spring. There is an advantage.

According to the fourth aspect of the present invention, in the above-described spring pressure adjusting device for a coil spring, there is an advantage that the spring pressure can be reliably adjusted by an extremely simple operation of twisting the operating shaft with a finger.

[Brief description of the drawings]

1A and 1B show a first embodiment of a spring pressure adjusting device for a coil spring according to the present invention, wherein FIG. 1A is a sectional side view in a state where spring pressure is set to be weak, and FIG. Sectional side view of the state set strongly.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 shows a detent means for a coil spring in another embodiment of the spring pressure adjusting device,
(A) is a cross-sectional front view of a main part of the second embodiment, and (B) is a cross-sectional front view of a main part of the third embodiment.

FIG. 4 is a cross-sectional side view of a main part showing a detent means for a coil spring in a fourth embodiment of the spring pressure adjusting device.

FIG. 5 is a cross-sectional side view of a main part showing a means for preventing a coil spring from rotating in a fifth embodiment of the spring pressure adjusting device.

6A and 6B show a conventional spring pressure adjusting means of a coil spring, wherein FIG. 6A is a cross-sectional side view of a main part of a conventional example by axial movement of a screw shaft, and FIG. Sectional side view of the principal part of the conventional example used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Pressed object 2a Spring receiving part 3 Coil spring 3a One end 3b Other end 31-33 Line end 4 Operating shaft 4a Screw shaft part 4b Head for twisting 5a, 5b Lock hole 6 Spiral groove 8 Linear guide groove

Claims (4)

[Claims] An operating shaft having a spiral groove corresponding to a spiral of a coil spring on a casing containing a body to be pressed and a coil spring for pressing the member is rotatable in a circumferential direction and cannot move in an axial direction. The other end of the coil spring, which is mounted and has one end pressed against the pressed body without the discarded winding portion, is screwed into a spiral groove of the operation shaft, and further includes a detent means for the coil spring. An apparatus for adjusting the spring pressure of a coil spring, wherein the spring pressure on the pressed body changes depending on the change in the screwing depth between the operating shaft and the coil spring accompanying the rotation operation of the shaft. 2. A spring pressure adjusting device for a coil spring according to claim 1, wherein the rotation preventing means of the coil spring is formed by a non-rotatable engagement between one end of the coil spring and the pressed body. 3. A coil spring detent means fits a wire end of the coil spring bent outward in the radial direction into a linear guide groove along an axial direction formed on a casing peripheral wall surrounding the coil spring. 2. A spring pressure adjusting device for a coil spring according to claim 1. 4. The coil spring according to claim 1, wherein the operating shaft has a shaft portion having a spiral groove on a peripheral surface and a torsion head disposed outside the casing. Pressure regulator.