JPH08135864A - Clamping device - Google Patents

Abstract

PURPOSE: To apply the uniform tightening force on the whole periphery of a jointed pipe, by installing a pair of tightening fitting bodies engaged at both the end parts of the tightening line wound in a spiral shape and a screwing means for tightening both the tightening fitting bodies, as for a clamping device suitable for clamping the joint part between the exhaust pipes of an automobile. CONSTITUTION: When the exhaust pipes 5 and 6 for automobile are connected, the downstream side exhaust pipe 6 is fitted with the exhaust pipe 5 on the upstream side, and the spiral-shaped tightening life 1 of a clamping device 4 is fitted on the outer periphery. The tightening line 1 is formed by winding a spring steel in a spiral form in the nearly 1.7 turns, and both the ends of the tightening line 1 are inserted into a hole 2d opened on the slide curved surfaces 2a of a pair of tightening fitting bodies 2, and the top end is caulked, and engaged with the slidable curved surface 2a by forming a head part 1a. Then, both the seat surfaces 2b and 2b are shifted, sliding along the outer peripheral surface (outer peripheral line) of the spiral-shaped tightening line 1 by tightening the nut 3B of a screwing means 3, and both the exhaust pipes 5 and 6 are tighetened by the tightening line 1 in a contracted diameter state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device suitable for clamping a joint between exhaust pipes of an exhaust system of an automobile.

[0002]

2. Description of the Related Art As a tightening tool (clamping device) for tightening and holding a rubber pipe inserting portion which is inserted and connected to a main tap such as a water faucet or a gas pipe end, the one disclosed in Japanese Utility Model Publication No. 50-23867 is well known.

This clamp device has a spiral tightening wire 31,
Each end 32, 32 of 31 is fixed to the fastener main body 33, and the spiral tightening line 31, with the shaft 34 screwed through the main body 33.
The upper part of the center of 31 is pressed by the pressing board 35 in the radial direction and both ends 32, 32 are pulled to reduce the diameter of the spiral tightening wires 31, 31 to tighten the rubber tube insertion part.

[0004]

According to the above-mentioned conventional technique, while pulling both ends 32, 32 of the spiral tightening wires 31, 31,
The upper part of the center is pressed by the presser plate 35 toward the center in the radial direction, so that the tightening lines 31 and 31 are not reduced in diameter while keeping a perfect circle, and the vertical direction in the drawing is deformed into an elliptical shape with a short diameter. . As a result, a uniform tightening force cannot be obtained on the circumference of the pipe, which may cause gas leakage when used in an exhaust system of an automobile.

Further, since the tightening shaft 34 extends radially in the radial direction of the pipe (the vertical direction in the drawing), the external shape of the clamp device becomes large, and when used as an exhaust pipe of a vehicle, peripheral parts are used. However, there was a problem that it was inferior in mountability on the vehicle.

[0006] Therefore, an object of the present invention is to provide a clamp device capable of solving such a risk of gas leakage and problems.

[0007]

In order to achieve the above object, a clamp device according to a first aspect of the present invention is such that a tightening wire (1) wound in a spiral shape and locked to both ends of the tightening wire (1), respectively. And a pair of fastening tool bodies (2) having a sliding curved surface (2a) to be slidably in contact with the outer peripheral surface of the fastening line (1) and a seating surface (2b) for screwing means, and the pair of fastening tools. And a screwing means (3) for fastening the pair of fastener main bodies (2) by engaging the seating surface (2b) of the attachment main body (2) and bringing both seating surfaces close to each other. To do.

A second aspect of the present invention is characterized in that, in the clamp device according to the first aspect, the seating surface (2b) for the screwing means of the fastener body (2) is formed into a convex curved surface. . The invention of claim 3 is the clamp device according to claim 1 or 2, characterized in that the tightening wire (1) is formed of spring steel.

[0009]

In the clamping device according to the first aspect, when the screwing means (3) is tightened, the sliding curved surfaces (2a) of the pair of tightening tool bodies (2) are attached to the outer peripheral surface of the spiral tightening line (1). Sliding along, they approach each other. In this way, both ends of the spiral tightening wire (1) are pulled in the circumferential direction of the tube, and a uniform tightening force acts on the entire circumference of the tube. Therefore, gas leakage is less likely to occur.

Further, since there is no tightening shaft protruding radially, the outer shape of the clamp device can be made small, so that the mountability on a vehicle or the like is improved. If the seating surface (2b) for the screwing means of the tightening tool body (2) is a convex curved surface, even if the tightening tool bodies are extremely close to each other due to a large tightening stroke, the bolts and nuts that are the screwing means are Since the seating surface (2b) is in contact with the center, it is possible to prevent a fold.

Further, when the spiral tightening wire is made of spring steel, it is possible to make both the diameter of the tightening wire and the high tensile strength compatible with each other, so that the tightening force can be further enhanced while keeping the perfect circle.

[0012]

1 (a) and 1 (b) show a first embodiment of the present invention.
1A is a plan view of the clamp device, FIG. 1B is a front view in which a part of the clamp device is broken, and FIG.
It is a vertical side view which shows the state which attached the clamp apparatus shown to (b) to the exhaust pipe.

In FIGS. 1 (a) and 1 (b), reference numeral 1 denotes a tightening wire wound in a spiral shape. Spring steel having a wire diameter of φ4.5 has an inner diameter of φ4.
It is spirally wound around a circle of 9 with about 1.7 turns. Reference numeral D indicates a circular diameter of φ49. The symbol d indicates the diameter of the tightening wire of φ4.5.

Reference numeral 2 denotes a pair of fastener main bodies, which are formed in a symmetrical shape to the left and right of the line Y-Y in the figure. These tightening tool bodies 2 are made by press-molding a metal plate, and extend along the outer peripheral surface (which may be technically called outer peripheral line) wound around the inner circumference D of the spiral tightening wire 1. Sliding surface 2 to be slid on
a and a seating surface 2b for a screwing means described later.

The sliding curved surface 2a is formed on the side contacting the spiral tightening line 1, and the seat surface 2b is formed on the side opposite to the sliding curved surface 2a. That is, a sliding curved surface 2a and a seating surface 2b are formed on one side and on the other side of the fastening tool body 2, respectively.

Reference numeral 2c denotes a rib, which is formed in front of and behind the sliding curved surface 2a and the seat surface 2b by bending in a direction perpendicular to the sliding curved surface 2d and the seat surface 2b, and enhances the rigidity of the fastener body 2. 3 is a screwing means, which is composed of a bolt 3A penetrating through a bolt hole formed in the seat surface 2b, 2b, a nut 3B screwed into the bolt 3A, and two washers 3C. By tightening the nut 3B, , The seat surfaces 2b, 2b of the pair of tightening tool bodies 2, 2 are brought close to each other to reduce the inner diameter D of the tightening wire 1 for tightening.

Both ends of the tightening wire 1 are passed through the sliding curved surfaces 2a of the tightening tool bodies 2 and 2 and the holes 2d formed in the sliding curved surfaces 2a are crimped to form the head portion 1a, whereby the sliding curved surface 2 is formed.
a, 2a.

In other words, the sliding curved surfaces 2a, 2a of the pair of tightening tool bodies 2, 2 are respectively locked to the ends of the spiral tightening wire 1. FIG. 1C shows a state in which the clamp device 4 having the configuration shown in FIGS. 1A and 1B is used for connecting an automobile exhaust pipe.

By fitting the exhaust pipe 6 on the upstream side to the exhaust pipe 6 on the upstream side, and fitting the spiral tightening wire of the clamp device 4 on the outer periphery thereof, and tightening the nut 3B of the screwing means 3,
The two seat surfaces 2b, 2b are brought close to each other. Then, the sliding curved surfaces 2a, 2a of the pair of tightening tool bodies 2, 2 have the spiral tightening line 1
The exhaust pipes 5 and 6 are fastened by the tightening line 1 while moving along the outer peripheral surface (outer peripheral line) of the.

FIG. 2 is a partially cutaway front view showing the fastener main bodies 2 and 2 used in the second embodiment of the present invention and the spiral fastening line 1. The second embodiment differs from the first embodiment only in that the seat surfaces 2b, 2b are formed into convex curved surfaces.

Therefore, both fastening tool bodies 2 and 2 are fastened with the bolts 3A and nuts 3B, and the seating surfaces 2b and 2b of both are fastened.
Since the seating surfaces 2b, 2b are always in contact with the center of the bolt / nut (strictly speaking, the central portion of the washer 3C, 3C when viewed from the front in the upper dimension in the drawing when viewed from the front) even when the bolts are approached,
It is possible to prevent the so-called creases on the nut seat surface. Therefore, the screwing means such as bolts and nuts can be tightened smoothly, and damage to the screwing means such as bolts and nuts due to an unreasonable load can be prevented.

Further, in both of the above-mentioned embodiments, since the spiral tightening wire is formed of spring steel, the wire diameter of the tightening wire can be reduced and high tensile strength can be achieved at the same time, so that a perfect circle having a diameter D is maintained. The tightening force can be further increased.

[0023]

Since the clamping device of the present invention is constructed as described above, it is possible to apply a uniform tightening force over the entire circumference of the pipes to be joined.

In addition, since the tightening force is always applied by the elasticity of the spiral tightening wire and the tightening tool body, even under severe environmental conditions such as temperature change and vibration like a joint of an exhaust pipe for a vehicle. Looseness and gas leakage can be reliably prevented.

Further, since the entire clamp device can be downsized, the mountability on a vehicle or the like is improved. Further, in the invention according to claim 2, since the bolt and the nut as the screwing means come into contact with the convex curved surface of the seating surface, the bolts and nuts are tightened extremely strongly and both seating surfaces (2
Even when b) and (2b) are extremely close to each other, the screwing means can be smoothly tightened, and breakage due to an excessive load on the screwing means can be prevented.

Furthermore, in the invention according to claim 3, since a spiral tightening wire having a small wire diameter can be used and a strong tightening force can be endured, the tightening wire is further adapted to the outer diameter of the pipe and deformed. And a strong tightening force can be generated. As a result, even when it is used in a portion such as an automobile exhaust pipe that repeatedly undergoes thermal expansion and contraction in a temperature cycle and is subjected to vibration and impact, it can be firmly tightened, and loosening and gas leakage can be prevented more reliably.

[Brief description of drawings]

FIG. 1A is a plan view of a first embodiment of the present invention, and FIG.
FIG. 3 is a front view of the same, and (c) is a vertical cross-sectional side view showing a state in which the clamp device of the first embodiment of (a) and (b) is used for a coupling portion of an exhaust pipe.

FIG. 2 is a front view of a second embodiment of the present invention.

FIG. 3 is a perspective view of a conventional technique.

[Explanation of symbols]

 1 Spiral tightening wire 2 Fastener body 2a Sliding curved surface 2b Seat surface 3 Screwing means 3A bolt 3B nut 3C washer

Claims (3)

[Claims] 1. A tightening wire (1) wound in a spiral shape, and a sliding curved surface (2a) to be slidably contacted with the outer peripheral surface of the tightening wire (1), which is locked to both ends of the tightening wire (1). And a pair of fastening tool bodies (2) provided with a seating surface (2b) for screwing means, and both seating surfaces by engaging with the seating surfaces (2b) of the pair of fastening tool bodies (2). And a screwing means (3) for fastening a pair of fastening tool bodies (2) by bringing them closer to each other. 2. A seat surface (2) for screwing means of a fastener body (2).
The clamp device according to claim 1, wherein b) is formed into a convex curved surface. 3. The clamping device according to claim 1, wherein the tightening wire (1) is made of spring steel.