JPH0735148A - Pin joint of linkage - Google Patents

Abstract

PURPOSE:To provide a pin joint of linkage, capable of simplifying a securing means in the case where an eccentric pin is secured to one side link and this linkage is operated, after positioning the link by the eccentric pin being fitted in a pin hole lying between both first and second links. CONSTITUTION:A column 7 of an eccentric pin 5 is fitted in a pin hole 2 of a first link 1 while another column 16 in a pin hole 15 of a second link 3, respectively, and this eccentric pin 5 is rotated and thereby both these links 1 and 3 are set in the specified position and then a square hole 19 of a stationary plate 18 is fitted in a regular hexagonal square pillar 17 of the eccentric pin 5 and this stationary plate 18 is welded to the second link 3 tight enough, thereby restraining any rotation of the eccentric pin 5 which is locked to the second link 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a link mechanism pin joint of a link mechanism used in a hydraulic turbine control device of a hydraulic power plant, in which an eccentric pin is fitted into a pin hole provided in each link to be connected. .

[0002]

2. Description of the Related Art A link mechanism is composed of links connected by pin joints and is used in a turbine control device for controlling guide vanes of Francis turbines and Kaplan turbines of hydroelectric power plants, and operates hydraulic or electric servomotors. Is transmitted to the guide vane by a link mechanism. In this case, in order to adjust the fully closed position of the guide vane, a pin joint provided with an eccentric pin for adjusting the link position is used in the link mechanism. As a pin joint of a link mechanism using such an eccentric pin, the one shown in FIG. 3 has been conventionally used.

In FIG. 3, 1 is a first link having a circular pin hole 2 and 3 is a second link having a tapered pin hole 4. The eccentric pin 5 is eccentric to the circular pin hole 2 of the first link 1 rotatably fitted in the circular pin hole 2 and the eccentric amount by which the position of the circular column 7 and the link can be adjusted. It is configured by integrating a truncated conical column 8 machined with the same taper as the pin hole 4 fitted into the pin hole 4 through a circular collar 6 and further providing a screw 9 on the end face of the truncated conical column 8. There is. In addition, 10 is a holding plate.

Here, the first link 1 and the second link 3
The column 7 of the eccentric pin 5 is inserted into the pin hole 2 of the first link 1 while the truncated conical column 8 is inserted into the pin hole 4 of the second link 3 with the collar 6 of the eccentric pin 5 being sandwiched therebetween. . On this occasion,
Since the eccentric pin 5 is eccentric, the position of the first link 1 and the second link 3 can be adjusted by rotating the eccentric pin 5. Therefore, the first and second links 1,
After adjusting 3 to a predetermined position, the nut 11 is screwed into the screw 9 to tighten the eccentric pin 5, and the eccentric pin 5 is moved by the frictional force between the pin hole 4 and the tapered portion of the truncated cone column 8 to move the eccentric pin 5 to the second link 3 Fixed to.

The pressing plate 10 is attached to the column 7 of the eccentric pin 5 with a bolt 13 to prevent the first link 1 from coming off. In such a pin joint in which the positions of the first and second links 1 and 3 are adjusted and the eccentric pin 5 is fixed to the second link 3, the first and second links 1 and 3 are Pin hole 2 of link 1 and this pin hole 2
The link mechanism including the first and second links 1 and 3 is operated by rotating between the column 7 and the column 7 which is fitted to the link mechanism.

[0006]

The eccentric pin 5 inserted into the pin holes 2 and 4 of the first and second links 1 and 3 as described above has the pin hole 4 of the second link 3 of the fixed portion. Since the truncated conical column 8 inserted into the column and the column 7 rotatably fitted in the pin hole 2 of the first link 1 are eccentric, when the link mechanism operates, the eccentric pin 5 is rotated. The moment to act acts. Therefore, the tightening force by the nut 11 is controlled so that the frictional force of the taper portion of the fixed portion overcomes the moment.

However, since the frictional force largely depends on the precision and roughness of the machined surface of the taper portion, it is difficult to obtain the required frictional force even if the nut tightening force is strictly controlled. There is a problem. Further, the machining of the taper portion requires high precision, which causes a problem that machining time and machining cost increase.

An object of the present invention is to provide a pin joint for a link mechanism that does not require the fixing portion of the eccentric pin fitted in the pin hole of the link to be connected to be fixed by frictional force.

[0009]

In order to solve the above problems, according to the present invention, an eccentric pin is provided in a circular pin hole provided in each of a first link and a second link provided in a link mechanism. In the pin joint of the link mechanism in which the first link is fitted, the first link being rotatably fitted in the pin hole of the first link.
And a second cylinder, which is eccentric with the first cylinder and fits into the pin hole of the second link, are axially connected and integrated, and further project from the end surface of the second cylinder. An eccentric pin provided with a polygonal prism and a fixing plate having a polygonal square hole into which the prism is fitted are provided, and first and second cylinders of the eccentric pin are provided as first and second link pins, respectively. The fixing plate is fitted into the hole, the square hole of the fixing plate is fitted into the prism, and the fixing plate is fixed to the second link by the fixing means.

The polygonal prism of the eccentric pin is a regular hexagonal prism. Further, the fixing means is assumed to be welding applied to the fixing plate and the second link.

[0011]

With the eccentric pin fitted in the circular pin hole provided in each of the first link and the second link, the first cylinder and the second cylinder eccentric to this cylinder are axially oriented. A fixing plate having a polygonal prism that protrudes from the end face of the second cylinder and a regular hexagonal prism as the prism, and further has a square hole into which the prism is fitted. The first cylinder of the eccentric pin is fitted in the pin hole of the first link, and the second cylinder is fitted in the pin hole of the second link, and the eccentric pin is rotated to rotate the first and second links. After the position adjustment, the square hole of the fixing plate is fitted to the prism of the eccentric pin, and the fixing plate is fixed to the second link by welding as the fixing means. As a result, the eccentric pin is fitted into the square hole of the fixing plate to which the prism protruding from the end face of the second cylinder is fixed, so that the rotation is restrained and fixed, and the first and second links are fixed to each other. The link mechanism operates by rotating between the pin hole of the link and the first cylinder of the eccentric pin.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a pin joint of a link mechanism according to an embodiment of the present invention, and FIG. 2 is a sectional view of the fixing plate portion of FIG. 1 and 2, the same parts as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted. 1 and 2 are different from the conventional example as follows.

The pin hole of the second link 3 is replaced with the circular pin hole 1
5, the eccentric pin 5 is provided with a column 16 that fits into the pin hole 15 instead of the conventional truncated cone column 8, and a regular hexagonal column 17 is provided on the end surface of the column 16. The fixing plate 18 is provided with a regular hexagonal square hole 19 into which the prism 17 of the eccentric pin 5 fits.

The eccentric pin 5 has the cylinder 7 and the cylinder 1.
6 is inserted into the pin hole 2 of the first link 1 and the pin hole 15 of the second link 3 with the collar 6 sandwiched therebetween. Then, the positions of the first link 1 and the second link 3 are adjusted to predetermined positions by the rotation of the eccentric pin 5, and then the prism 17 of the eccentric pin 5 is fitted into the square hole 19 of the fixing plate 18, Fixed plate 18
Is fixed to the second link 3 by welding as fixing means. In this case, since the eccentric pin 5 has a regular hexagonal prism 17 fitted in the square hole 19 of the fixing plate 18 fixed to the second link 3, the rotation of the eccentric pin 5 is restricted. It will be fixed at 3.

The pressing plate 21 has the eccentric pin 5 and the bolt 2 attached thereto.
The second link 3 attached by means of 2 and having the fixing plate 18 attached thereto is prevented from being pulled out. In the pin joint for connecting the first and second links 1 and 3 having the fixed eccentric pin 5 with such a configuration, the first and second links 1 and 3
Rotates between the pin hole 2 of the first link and the cylinder 7 of the eccentric pin 5, and the link mechanism including the first and second links 1 and 3 operates.

[0016]

As is apparent from the above description, according to the present invention, since the eccentric pin has the fixing plate to which the prism is fitted, it is fixed to one of the links by welding as the fixing means. The eccentric pin is fixed to this link, thus without relying on the unstable frictional forces as in the past,
Since the eccentric pin can be fixed and the taper processing is unnecessary, the processing time and the processing cost are reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a pin joint of a link mechanism according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line AA of the fixing plate portion of FIG.

FIG. 3 is a sectional view of a pin joint of a conventional link mechanism.

[Explanation of symbols]

 1 1st link 2 Pin hole 3 2nd link 7 Cylinder 15 Pin hole 16 Cylinder 17 Square column 18 Fixing plate 19 Square hole

Claims (3)

[Claims] 1. A pin joint of a link mechanism, wherein an eccentric pin is fitted in circular pin holes provided in each of a first link and a second link provided in the link mechanism.
A first cylinder that is rotatably fitted in the pin hole of the link and a second cylinder that is eccentric to the first cylinder and that fits in the pin hole of the second link are connected in the axial direction. The eccentric pin provided with a polygonal prism that projects from the end face of the second cylinder, and a fixing plate having a polygonal square hole into which the prism fits. And the second cylinder are fitted into the pin holes of the first and second links, respectively, the square holes of the fixing plate are fitted to the prisms, and the fixing plate is fixed to the second link by the fixing means. The pin joint of the characteristic link mechanism. 2. The pin joint for a link mechanism according to claim 1, wherein the polygonal prism of the eccentric pin is a regular hexagonal prism. 3. The pin joint of a link mechanism according to claim 1, wherein the fixing means is welding applied to the fixing plate and the second link.