JP2005265766A - Test hammer, and lid material device for test hammer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a test hammer capable of correcting easily a precision error before delivery, while preventing as much as possible the precision error from being generated after delivered. <P>SOLUTION: This test hammer is provided with a plunger 1 for hammering a measuring objective face 2, in a cylindrical body 3, a hammer 14 for hammering the plunger 1, a cushioning member 15 for moderating force pushing back the hammer 14 by jumping-back of the plunger 1 hammered by the hammer 14 from the measuring objective face 2, and a support member 7 for supporting the cushioning member 15. The test hammer has a lid main body 11 for covering a base end part opening of the cylindrical body 3, and a screw member 20 with a tip part screwed in the lid main body 11. A screwed-in amount of the screw member 20 is regulated to change a distance from the support member 7 up to the lid main body 11, and cushioning force of the cushioning member 15 is regulated thereby. The screwed-in amount of the screw member 20 is made not to allow reregulation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a test hammer for measuring compressive strength of concrete or the like and a lid material device provided in the test hammer.

  Currently, a non-destructive compact test hammer called Schmitt hammer (trade name) is widely used for compressive strength measurement of concrete and the like. As shown in FIG. 1, the test hammer generally includes a plunger 1 that strikes a measurement target surface such as a concrete surface, a hammer 14 that strikes the plunger 1, and a plunger 1 that is struck by the hammer 14. Mainly includes a buffer member 15 such as a spring that buffers the force that bounces back from the measurement target surface 2 and pushes back the hammer 14, and a support member 7 that supports the buffer member 15. It is provided within. The test hammer 30 detects the compressive strength of the measuring object 2 based on the distance by which the hammer 14 is pushed back.

  Further, the test hammer 30 includes a lid material device having a lid body 11 that covers the base end opening of the cylindrical body 3 and a screw member 20 having a distal end 20A screwed into the lid body 11. In addition, the buffering force of the buffer member 15 can be adjusted by changing the distance of the support member 7 to the lid body 11 by adjusting the screwing amount of the screw member 20.

  Since the test hammer 30 has individual differences in measurement accuracy, the test hammer 30 is shipped after the accuracy is inspected by a tester such as a test anvil and the error is corrected by adjusting the screwing amount of the screw member 20.

  However, in spite of such strict accuracy control, it has become clear from recent survey reports that an accuracy error actually occurs. Therefore, as a result of investigations by the present inventors, it has been found that this accuracy error is caused by adjusting the screwing amount of the screw member 20 after shipment. In this regard, it may be possible to press-fit a pin into the lid body 11 in place of the screw member 20 so that adjustment is not possible after shipment. Things must be inserted and removed, which is too inefficient and uneconomical.

  SUMMARY OF THE INVENTION A main object of the present invention is to provide a test hammer and a cover device for a test hammer that can easily correct an accuracy error before shipment while preventing occurrence of an accuracy error after shipment as much as possible.

The present invention that has solved the above problems is as follows.
[Invention of Claim 1]
Plunger for striking the surface to be measured, hammer for striking the plunger, a buffer member for buffering the force of the plunger struck by the hammer rebounding from the surface to be measured and pushing back the hammer, and the buffer member And a support member that supports the sensor, and detects the compressive strength of the measurement object based on the distance by which the hammer is pushed back.
A lid member main body covering the base end opening of the cylindrical body; and a screw member having a distal end screwed into the lid member main body, and the screwing amount of the screw member is adjusted, thereby adjusting the support member. A test hammer in which the distance to the lid body is changed to adjust the buffering force of the buffer member,
A test hammer characterized in that the screwing amount of the screw member cannot be readjusted.

[Invention of Claim 2]
The test hammer according to claim 1, wherein the screwing amount cannot be readjusted by being bonded, brazed or welded to the lid body.

[Invention of Claim 3]
The screw member has a screw portion and a head portion thicker than the screw portion,
The entire part of the screw member protruding from the lid material body is surrounded by a cylinder, and at least a part of the part corresponding to the screw part of the cylinder is tightened so as to be thinner than the head. The test hammer according to claim 1.

[Invention of Claim 4]
Plunger for striking the surface to be measured, hammer for striking the plunger, a buffer member for buffering the force of the plunger struck by the hammer rebounding from the surface to be measured and pushing back the hammer, and the buffer member And a support member that supports a test hammer that detects a compressive strength of an object to be measured based on a distance by which the hammer is pushed back.
A lid member main body covering the base end opening of the cylindrical body; and a screw member having a distal end screwed into the lid member main body, and adjusting the screwing amount of the screw member to adjust the lid of the support member A lid device that can adjust the buffering force of the buffer member by changing the distance to the material body,
A lid device for a test hammer, characterized by comprising means for preventing the screw member from being re-adjusted.

  According to the present invention, it is possible to easily correct the accuracy error before shipment while preventing the occurrence of accuracy error after shipment as much as possible.

  Embodiments of the present invention will be described below. Since the basic configuration of the test hammer of the present embodiment is the same as that of the conventional test hammer 30 shown in FIG. 1, the following points will focus on differences from the conventional test hammer, points not described above, and usage methods. explain.

  As shown in FIG. 1, the test hammer 30 is provided on the base end surface 14 </ b> C of the hammer 14 with a receiving locking portion 14 </ b> A that protrudes toward the lid body 11 and has a distal end portion that extends outward. Prior to the start of measurement, the receiving locking portion 14A is locked by a locking portion 13A that protrudes inwardly at the distal end portion of the saddle 13. Thereby, the hammer 14 is fastened while being pulled toward the base end side.

  In measuring the compressive strength, the push button 6 is pushed inward (toward the axis of the cylinder 3) after bringing the tip of the plunger 1 into contact with the surface to be measured perpendicularly. The push button 6 is pushed back by a spring 6B which is an elastic member. When the push button 6 is pushed back, the hook 6A spreading outward from the tip of the push button 6 is caught by the tip of the saddle 13 and the tip of the saddle 13 is pushed. The part is shifted outward. As a result, the locking relationship between the locking portion 13A of the thread 13 and the receiving locking portion 14A of the hammer 14 is canceled, and the hammer 14 is pulled toward the distal end side by the spring 16 and strikes the plunger 1. By this impact, the plunger 1 strikes and bounces the measurement target surface 2 and pushes back the hammer 14. However, this pushing back force is weakened by the buffer member 15 such as a spring.

  The buffer member 15 is fixed to the distal end portion of the support member 7 fitted into the plunger 1 from the proximal end side. In addition to supporting the buffer member 15, the support member 7 also serves as a guide for guiding the movement of the hammer 14 in the longitudinal direction of the cylinder 3.

  When the hammer 14 is pushed back by the plunger 1, a stepped portion 14 </ b> B formed around the central peripheral wall of the hammer 14 extends from the front end surface of the rebound value display material 4 obliquely inward. I get caught in 4A. Due to this catch, the rebound value display material 4 moves to the base end side, and this movement amount (distance) is recognized as a rebound value from the repulsion value display window 19, and the compression strength is detected.

  On the other hand, a disc 8 having a substantially circular cross section is provided at the base end portion of the support member 7, and a spring member is provided on the base end side surface of the disc 8 so as to extend toward the base end side. 12 is attached. The distal end portion of the spring member 12 is inserted into a groove 11A formed in the lid member main body 11 along the circumference thereof.

  A front end portion of the screw member 20 is screwed into a substantially central portion of the lid body 11. The screw member 20 is mainly composed of a screw portion 20A and a head portion 20B thicker than the screw portion 20A, and examples thereof include screws and bolts. In the present embodiment, a lock nut 21 is provided in the middle of the threaded portion 20A. By moving (tightening) the lock nut 21 to the lid body 11 side, an unintended change in the screwing amount is ensured. To be prevented. The screw member 20 thus provided comes into contact with the base end portion of the support member 7 receiving the force toward the base end side by the buffer member 15 via the saddle 13 and the disk 8. Therefore, when the screwing amount of the screw member 20 is adjusted, the distance from the support member 7 to the lid body 11 is changed accordingly, and the buffering force of the buffer member 15 is adjusted. By adjusting the buffering force, the movement amount (repulsion value) of the repulsion value display material 4 can be accurately associated with the actual compressive strength.

  In the test hammer of the present invention, a non-adjustable means is provided so that the screwing amount of the screw member 20 cannot be readjusted after shipment (the lid body 11, the screw member 20 and the non-adjustable means, The device is configured.) Examples of the method for making it impossible to readjust the screwing amount include a method of bonding the tip of the screw member 20 to the lid body 11, a method of brazing, and a method of welding.

  However, according to these methods, even if readjustment by the user becomes impossible, if an error in accuracy occurs due to another factor, correction (repair) cannot be performed. In addition, it is conceivable to cover the projecting portion of the screw member 20 from the lid body 11 with an expandable tube, or to apply a seal, tape, or the like to the projecting portion. Can not cope with intentional readjustment. Furthermore, although fixing with a split pin, a lock screw, or a wire is conceivable, the screw member 20 needs to be processed, which is not preferable in terms of labor and cost.

  Therefore, as shown in FIG. 2, for example, a method of using a cylindrical member 31 made of iron, aluminum, or the like and having substantially circular cross sections with both end edges open is recommended. In this method, the cylindrical member 31 is attached so as to surround the entire portion of the screw member 20 protruding from the lid body 11 and at least a part of the portion corresponding to the screw portion 20A of the cylindrical member 31 is attached to the head portion 20B. Tighten (crimp) so that it becomes thinner. Thereby, after shipment, the user of the test hammer cannot readjust unless the user has a special tool, and the occurrence of an accuracy error is prevented as much as possible. In addition, there is an advantage that repair in the case of an accuracy error due to another factor is not impossible.

  As described above, when the test hammer 30 is shipped with the cylindrical member 31 provided, the head of the cylindrical member 31 may be further sealed with a seal or the like to indicate that the accuracy has been confirmed. As a result, readjustment is prevented in a tangible and intangible manner, and the reliability of the test hammer 30 is further increased.

It is a longitudinal cross-sectional view of a test hammer. It is an example of construction of a readjustment prevention means.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Plunger, 2 ... Measuring object, 3 ... Cylindrical body, 11 ... Lid body main body, 14 ... Hammer, 15 ... Buffer member, 20 ... Screw member, 20A ... Screw part, 20B ... Head, 31 ... Cylindrical member .

Claims (4)

Plunger for striking the surface to be measured, hammer for striking the plunger, a buffer member for buffering the force of the plunger struck by the hammer rebounding from the surface to be measured and pushing back the hammer, and the buffer member And a support member that supports the sensor, and detects the compressive strength of the measurement object based on the distance by which the hammer is pushed back.
A lid member main body covering the base end opening of the cylindrical body; and a screw member having a distal end screwed into the lid member main body, and the screwing amount of the screw member is adjusted, thereby adjusting the support member. A test hammer in which the distance to the lid body is changed to adjust the buffering force of the buffer member,
A test hammer characterized in that the screwing amount of the screw member cannot be readjusted.   The test hammer according to claim 1, wherein the screwing amount cannot be readjusted by being bonded, brazed or welded to the lid body. The screw member has a screw portion and a head portion thicker than the screw portion,
The entire part of the screw member protruding from the lid material body is surrounded by a cylinder, and at least a part of the part corresponding to the screw part of the cylinder is tightened so as to be thinner than the head. The test hammer according to claim 1. Plunger for striking the surface to be measured, hammer for striking this plunger, buffer member for buffering the force of the plunger struck by the hammer rebounding from the surface to be measured and pushing back the hammer, and this buffer member And a support member that supports a test hammer that detects a compressive strength of an object to be measured based on a distance by which the hammer is pushed back.
A lid member main body covering the base end opening of the cylindrical body; and a screw member having a distal end screwed into the lid member main body, and the lid of the support member is adjusted by adjusting a screwing amount of the screw member. A lid device that can adjust the buffering force of the buffer member by changing the distance to the material body,
A lid device for a test hammer, characterized by comprising means for preventing the screw member from being re-adjusted.

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