JP3280811B2 - cover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover used for dust protection and waterproofing. For example, in a mechanism in which an operating member such as a tracing stylus is projected from a main body case and the operating member is supported so as to be movable in a direction orthogonal to the axis thereof, the mechanism can be used as a cover between the main body and the operating member. .

[0002]

2. Description of the Related Art A measuring instrument has a structure in which an operating member such as a spindle or a probe is projected from a main body case and a detector for detecting a displacement amount of the operating member as an electric signal is built in the main body case. A waterproof and dustproof structure is required to prevent water, oil, dust and the like from entering the main body case. As one of the conventional waterproof and dustproof structures, for example, in the case of a dial gauge in which a spindle is protruded from a main body case and a detector for detecting an axial movement amount of the spindle as an electric signal is built in the main body case. There is known a structure in which a bellows which expands and contracts with the movement of the spindle is provided between a portion of the main body case where the spindle projects and the tip of the spindle.

[0003]

THE INVENTION to be solved INVENTION Normally, bellows, good stretch and force F ₁ with respect to the axis direction of the bellows, as shown in FIG. 7, with respect to the bending force F ₂ with respect to the axis of the bellows, as shown in FIG. 8 As described above, when used as a waterproof / dustproof cover for a dial gauge in which the spindle moves in the axial direction relative to the main body case, as described above, the waterproof / dustproof function is provided without hindering the movement of the spindle. Can demonstrate.

However, the inner and outer measuring devices, that is, the pair of measuring elements are brought into contact with the measuring part of the object to be measured while approaching and separating while keeping the posture parallel to each other. When used as a waterproof or dustproof cover for an inside / outside measuring device for measuring an inside dimension (for example, an inner diameter of a hole) or an outer dimension (for example, an outer diameter of a shaft) of an object, there are the following problems. .

That is, as shown in FIG.
The inner case and the outer case in which the tracing stylus 2 protruded from the main body is displaced in the direction orthogonal to the axis thereof, and
If the measuring element 2 is used bellows 4 as a cover for closing the hole 3 which projects, because must combine characteristics of FIGS. 7 and 8 against the force F _3, after all, the total length of the bellows 4 L
Need to be longer. However, when the total length L of the bellows 4 increases, the total length of the tracing stylus 2 must also be increased, and the length L of the tracing stylus 2 from the drive system 5 for displacing the tracing stylus 2 to the locking portion of the bellows 4 _{Since 0} becomes longer, a problem arises in that the accuracy of motion transmission is reduced due to the relationship between moments.

Therefore, as a cover having a structure in which the tracing stylus 2 protruding from the main body case 1 is displaced in a direction orthogonal to the axis thereof, a diaphragm-shaped cover used for a joystick, that is, a main body and an operating rod are used. It is conceivable to use a rubber diaphragm-like cover provided between them. However, even with a rubber diaphragm cover, the deformation is not always sufficient (easy) for a small external force in the radial direction, and the diaphragm cover becomes resistant to the displacement of the measuring element of the inner and outer measuring instruments. There remains a problem that smooth movement of the tracing stylus cannot be guaranteed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cover which solves the above-mentioned conventional drawbacks, is compact and does not hinder the movement of an operating member such as a measuring element.

[0008]

The cover of the present invention is made of a flexible material and has a cross section of an outer peripheral inclined wall, an end face, and an end surface.
An annular protrusion having a trapezoidal convex shape having an inner peripheral inclined wall and being continuous along the circumferential direction, forming a bellows which can be extended and contracted along the circumferential direction of the annular protrusion, and Perimeter
A first fixing portion is provided on the outer peripheral edge of the inclined wall , and a second fixing portion is provided on the inner peripheral edge of the inner peripheral inclined wall of the annular projection.

[0009]

For example, when used as a cover for an inner / outer measuring instrument, the first fixing portion is engaged with the main body case, and the second fixing portion is engaged with the tracing stylus. Here, when the tracing stylus moves in a direction perpendicular to its axial direction, the annular
A tensile force acts on the protrusion in the direction of movement of the tracing stylus and a compressive force acts on the opposite side, but these are absorbed by the bellows of the annular protrusion. In other words, the ring on the side where the tensile force acts
The ring on the side where the bellows of the protruding part expands in the circumferential direction and the compressive force acts
The bellows of the protruding portion shrinks in the circumferential direction . At the same time, the tracing stylus moves in the same direction, of the annular projection of the cover, the interval of the trapezoidal convex portions of the annular projection of the moving direction of the tracing stylus is compressed and deformed, the annular collision opposite to that Since the interval between the trapezoidal convex portions of the portion is expanded and deformed, the movement of the tracing stylus is hardly hindered, and stable movement of the tracing stylus can be secured. In addition,
The first solid is attached to the outer peripheral edge of the outer peripheral inclined wall of the annular projection having a trapezoidal convex surface.
The second fixed part is provided on the inner peripheral edge of the inner peripheral inclined wall of the annular projection.
Since a structure in which each Ki de short dimension from the driving system of the probe to a second fixed part of the cover, also prevent reduction in the motion transmission accuracy. Needless to say, it is not necessary to secure the entire length longer than that of the conventional bellows, so that it can be made compact.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment in which the cover of the present invention is applied to an inner measuring device. The inner measuring device A has a pair of tracing styluses 2A and 2B arranged on a main body case 1 in a state where the pair of tracing styluses 2A and 2B are parallel to each other and a tip end portion thereof protrudes from the main body case 1. A moving mechanism (not shown) for moving in the direction of approaching and separating from the posture and a detector (not shown) for detecting the distance between the pair of measuring elements 2A and 2B are provided.
Cover 6 so as to cover holes 3A and 3B from which A and 2B protrude.
Are provided along the circumference of each of the tracing styluses 2A and 2B.

As shown in FIGS. 2, 3 and 4, the cover 6 has a hole 11 in the center by a flexible material, here rubber, and has a trapezoidal convex cross section. An annular protrusion 12 is formed continuously along the circumferential direction.
The annular protrusion 12 has a bellows 13 which can be extended and contracted along its circumferential direction, and a first fixing portion 14 is provided on an outer peripheral edge of the annular protrusion 12 and a first fixing portion 14 is provided on an inner peripheral edge of the annular protrusion 12. Two fixing portions 15 are integrally formed.

The bellows 13 are formed integrally with grooves 13A at a constant pitch along the circumferential direction of the annular projection 12. The groove 13A is formed along the outer peripheral inclined wall 12A, the end surface 12B, and the inner peripheral inclined wall 12C in the trapezoidal convex cross section of the annular protrusion 12, and gradually becomes deeper from the outer peripheral inclined wall 12A toward the end surface 12B. Moreover, it is formed so that it may become shallower gradually from the end face 12B toward the inner peripheral inclined wall 12C. The first fixing part 14 is fixed to the front end wall of the main body case 1, and the second fixing part 15 is locked to each of the tracing styluses 2A and 2B. Here, the second fixing portion 15 is provided with the annular protrusion 12.
In the direction of the protrusion of the first fixing portion 4.

With such a configuration, the tracing stylus 2A,
When the cover 2B moves downward in FIG. 4, a tensile force acts on the cover 6 on the moving side of the tracing styluses 2A and 2B, and a compressive force acts on the opposite side, as shown in FIG. Then, the bellows 13
Since the side on which the tensile force acts expands and the side on which the compressive force acts contracts, movement of the tracing styluses 2A and 2B is hardly hindered, and smooth movement of the tracing styluses 2A and 2B can be guaranteed. At the same time, when the tracing styluses 2A and 2B move downward in FIG. 4, as shown in FIG. 5, the moving side of the stylus 2A and 2B in the annular protrusion 12 of the cover 6 is compressed and deformed. The opposite side is expanded and deformed.

Therefore, according to this embodiment, the bellows 13 are formed along the circumferential direction on the annular projection 12 formed of a flexible material, and the first projection is formed on the outer peripheral edge of the annular projection 12. The fixing portion 14 is provided on the inner peripheral edge of the annular
Since the fixing portions 15 are integrally formed, resistance to movement (movement in a direction perpendicular to the axis) of the tracing styluses 2A and 2B fixed to the second fixing portion 15 may be generated. Since the number is small, smooth movement of the tracing styluses 2A and 2B can be guaranteed.

Further, since the second fixing portion 15 is provided at a position close to the first fixing portion 14 in the projection direction of the annular protrusion 12, the driving system of the tracing styluses 2A and 2B is provided with a cover 6. Since the dimension up to the second fixing portion 15 can be shortened, a decrease in motion transmission accuracy can be prevented. Needless to say, it is not necessary to secure the entire length longer than that of the conventional bellows, so that a compact structure can be achieved. In addition, airtightness can be sufficiently ensured.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and can be modified without departing from the scope of the present invention. For example, in the cover 6 of the above embodiment, the groove 13
A is the outer peripheral inclined wall 12A, the end face 12B, and the inner peripheral inclined wall 1
2C, but as shown in FIG. 6, the groove 13B of the outer peripheral inclined wall 12A and the inner peripheral inclined wall 12C and the end face 1
The groove portions 13C of the 2B may be configured so as not to be continuous and alternately continuous along the circumferential direction.

In the above embodiment, the cover 6 is formed of rubber. However, the cover 6 is not limited to rubber, but may be any other material such as synthetic resin as long as it has flexibility . Further, in the above embodiment, the groove 1 is formed over the entire area of the annular protrusion 12 in the circumferential direction.
Although the grooves 3A, 13B, and 13C are formed, the grooves 13A, 13B, and 13C may be formed at regular intervals. Further, in the above-described embodiment, an example in which the present invention is applied to the inner measuring device has been described. However, the present invention is not limited to this.

[0018]

According to the cover of the present invention, it is possible to provide a cover which is compact and does not hinder the movement of the operating member such as the measuring element.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to an inner measuring device.

FIG. 2 is a perspective view showing a cover of the embodiment.

FIG. 3 is a front view showing a cover of the embodiment.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a diagram showing a state of a cover when a probe moves in the embodiment.

FIG. 6 is a diagram showing another embodiment of the present invention.

[7] Conventional bellows is a diagram showing a state of expansion and contraction with respect to the axial force F _1.

[Figure 8] conventional bellows is a diagram showing a state of expansion and contraction with respect to the bending force F ₂ with respect to the axis.

FIG. 9 is a diagram applied to a conventional measuring instrument having a tracing stylus that moves a bellows in a direction perpendicular to an axis.

[Explanation of symbols]

 Reference Signs List 6 Cover 12 Annular projection 13 Bellows 14 First fixing part 15 Second fixing part

Continuation of front page (56) References JP-A-2-176273 (JP, A) JP-A-59-137648 (JP, A) JP-A-59-188354 (JP, U) JP-A-49-105776 (JP, A) , U) Japanese Utility Model Showa 55-131712 (JP, U) Japanese Utility Model Application Hei 4-71822 (JP, U) Japanese Patent Publication No. 38-13819 (JP, B1) Japanese Utility Model Showa 36-18604 (JP, Y1) (58) Field surveyed (Int.Cl. ⁷ , DB name) F16J 15/52 F16D 3/84 A F16D 3/84 G F16D 3/84 J F16J 3/04 B F16J 3/04 Z

Claims (1)

(57) [Claims] 1. A cross-section is made of a flexible material.
Trapezoidal convex shape with peripheral inclined wall, end face and inner peripheral inclined wall
One circumferential direction along to form an annular projection continuous to form a stretchable bellows along the circumferential direction of the annular projection, and,
A cover, wherein a first fixing portion is provided on an outer peripheral edge of an outer peripheral inclined wall of the annular protrusion, and a second fixing portion is provided on an inner peripheral edge of an inner peripheral inclined wall of the annular protrusion.