JPH0346357Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) This invention relates to a device for measuring the hardness of the inner surface of a relatively small diameter cylindrical body such as a cylinder of an internal combustion engine.

(Prior art) Until now, in order to measure the internal hardness of a relatively small-diameter cylindrical body, the sample inspection method was used to cut an arbitrary product in the axial direction and determine the hardness of Vickers or Brinell. measures are commonly taken. However, this conventional method has the disadvantage that cutting is time-consuming and the product is wasted.

On the other hand, as a method that does not cut the product, Tokkosho
No. 56-25972 has been proposed. This means
The Pickers indenter is pressed against the inner surface of the cylindrical body by a lever-like beam linked to a threaded rod, and cutting is not required, but because it is a lever method, there is a limit to high pressure output, and it is difficult to use 2-ton or 3-ton pressure. It is impossible to obtain output. In addition, in the lever method, since the force point is rotational torque, a biased pressing force is transmitted in the axial direction of the indenter, and therefore, in a strict sense, precision in indentation formation cannot be expected. Furthermore, the use of a lever method significantly narrows the range of diameters of the cylindrical body that can be measured.

(Problems to be solved by the invention) The present invention was made based on the conventional situation, and is capable of exerting sufficient pressure even on a cylindrical body made of cast metal, etc., and has a piston indenter. We would like to provide a measuring indenter device that can be expected to press accurately in the horizontal direction and make highly accurate indentations, and that is suitable for measuring the inner surface of small diameters, and that can also be applied to cylindrical bodies with a considerable diameter range. It is something to do.

[Structure of the invention] (Example) The following will be described with reference to an example shown in the drawings. In FIG. 1, M indicates an apparatus main body, and P indicates a cylindrical body which is an object to be measured.

The apparatus main body M is attached to an oil feed pipe 1 of a known hydraulic Brinell hardness tester main body (not shown). That is, a vertical connecting pipe 2 is connected to the tip of the oil feed pipe 1, which is movable up and down, so as to be pivotable to the oil feed pipe 1. and the tip opening 2 of the vertical connection pipe 2
a is connected to the axial base of a horizontally oriented cylinder 3 whose back wall outer surface 3a is formed into an arc shape, and communicates with the hydraulic chamber 4 within the cylinder 3. And this hydraulic chamber 4
A piston indenter 5 is provided within the cylinder 3 with a return spring 6 interposed between it and the front wall 3b of the cylinder 3, and a female threaded portion 5a is provided at the tip of the piston indenter 5.
A male threaded portion 7b of a ball receiving member 7 protruding outside the front wall 3b is screwed into the female threaded portion 5a. Then, a carbide ball 8 is fitted into a saucer portion 7a formed at the tip of the ball receiving member 7, and a ball cap 9 is formed which has a ball viewing hole 9a in the center.
is fitted to the outside of the tip of the ball receiving member 7, thereby fixing the ball 8. In addition, the axially eccentric portion of the piston indenter 5 has a function of preventing excessive protrusion of the piston indenter 5 by releasing oil to the front space 4a of the piston indenter 5 when the piston indenter 5 exceeds a required stroke. A safety valve 10 is provided, and a return pipe 16 communicating with the front space 4a is connected to the front part of the cylinder 3 correspondingly.

More specifically, the middle safety valve 10 includes a pressure communication passage 11 that communicates the hydraulic chamber 4 and the front space 4a.
A ball valve 13 is always pressed by a spring 14 to a valve seat 12 formed in the middle thereof, and a valve rod 15 inserted into the pressure communication passage 11 with its tip 15a protruding into the front space 4a is retracted. When I did,
The ball valve 13 is moved away from the valve seat 12 against the force of a spring 14. Further, the carbide ball 8 may be fixed to the saucer portion 7a,
In order to ensure smooth centering work, which will be explained later,
It is desirable to be able to roll freely relative to the saucer portion 7a.

(Function) Now, in order to measure the inner surface hardness of the cylindrical body P using the device main body M having the above configuration, first the device main body M
is lowered to an appropriate position within the fixed fixed cylindrical body P, and as shown in FIG. It is fixed at a point where the center of the outer surface 3a of the back wall is inscribed in vertical line contact. Then, the axis of the piston indenter 5 is determined at the longest distance of the diameter of the cylindrical body P, that is, the diameter. Then, the body of the Brinell hardness tester is operated to feed oil at a predetermined pressure into the hydraulic chamber 4 of the cylinder 3 through the oil feed pipe 1. Then, the piston indenter 5 is pushed forward against the return spring 6 by the output, and the carbide ball 8 at the tip pressurizes the inner surface of the cylindrical body P (FIG. 3). In this case, if the ball 8 is given rolling properties, the centering error can be easily corrected due to its sliding effect.

During pressurization, when the piston indenter 5 exceeds a required stroke, the safety valve 10 operates to release excess hydraulic pressure to the space 4a in front of the piston indenter 5. More specifically, when the piston indenter 5 moves forward beyond a certain limit, the tip 15a of the valve stem 15 of the safety valve 10
hits the cylinder front wall 3b, and the ball valve 13
The valve seat portion 12 is opened by retreating against the spring 14. As a result, a part of the oil in the hydraulic chamber 4 passes through the pressure communication path 11 to the front space 4a of the piston indenter 5.
It plays the role of preventing excessive protrusion. The excess oil that is continuously sent is removed from the feed pipe 16.
(Fig. 4).

After a predetermined period of time has elapsed, the oil in the hydraulic chamber 4 is drained by operating the testing machine main body (by opening the pressure reducing valve of the testing machine main body), and the piston indenter 5 is restored to its original state by the action of the return spring 6. Therefore, the device main body M is raised and removed from the cylindrical body 1, and then the indentation formed on the inner surface of the cylindrical body 1 is measured by a conventional method to calculate the hardness.

[Effects of the invention] As described above, the present invention enables the measurement of the inner surface hardness of a cylindrical body, which conventionally requires a large amount of processing time and loss, to be performed quickly, easily, and accurately using the cylindrical body as it is. be. Also, as mentioned at the beginning, compared to conventionally proposed lever-type cylindrical object measuring instruments, because it is a hydraulic type, the desired pressure can be obtained depending on the material of the object to be measured (2 ton, 3 ton pressure). ),
It has advantages such as high accuracy can be achieved because the pressing force is reliably applied in the horizontal direction, and the ball receiving member 7 can be changed in length and length, and the diameter range of the cylindrical body that can be measured is significantly increased.

Furthermore, centering work within the diameter of the cylindrical body 1 can be performed quickly by simply inscribing the center of the arc-shaped outer surface 3a of the circular back wall of the cylinder 3. For example, as described above, the centering error can be easily corrected.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a longitudinal side view, Fig. 2 is a plan view, Fig. 3 is a longitudinal side view in the operating state (immediately before pressurization), and Fig. 4 is the same in the operating state. Vertical side view (at the time of pressurization). DESCRIPTION OF SYMBOLS 1... Oil feed pipe, 2... Vertical connection pipe, 2a... Its tip opening, 3... Horizontal cylinder, 3a... Its arcuate back wall outer surface, 3b... Its front wall, 4... Hydraulic chamber, 4a...
Front space, 5... Piston indenter, 6... Return spring, 7
...ball receiving member, 7a...its saucer portion, 8...carbide ball, 9...ball cap, 9a...ball peephole, 10...safety valve, 16...return pipe.

Claims (1)

[Claims for Utility Model Registration] 1. A vertical connection pipe 2 is connected to the tip of the oil feed pipe 1 of the body of the Brinell hardness tester so as to be freely pivotable to the oil feed pipe 1, and the tip opening 2a of the vertical connection pipe 2 is ,
The outer surface 3a of the back wall is connected to the axial base of the horizontal cylinder 3 formed in an arc shape and communicates with the hydraulic chamber 4 in the horizontal cylinder 3, and the piston indenter 5 is inserted into the hydraulic chamber 4. A return spring 6 is interposed between the front wall 3b of the piston indenter 5 and the front wall 3b of the piston indenter 5.
b Connecting the ball receiving member 7 projecting outside in a replaceable manner, and fitting the carbide ball 8 into the saucer portion 7a of the ball receiving member 7 and the ball cap 9 having a ball viewing hole 9a in the center. In addition, a safety valve 10 is provided at the axially eccentric portion of the piston indenter 5 to release oil to the front space 4a of the piston indenter 5 when the piston indenter 5 exceeds a required stroke. The front space 4 is located in the front part of the
A hydraulic indenter device for measuring the inner surface hardness of a cylindrical body, characterized in that a feed pipe 16 is connected to the a. 2 The carbide ball 8 is placed in the saucer portion 7 of the carbide ball 8.
The hydraulic indenter device for measuring the inner surface hardness of a cylindrical body according to claim 1, which is capable of rolling freely relative to a.