JPH08292002A - Readout method of depth of screw and device thereof - Google Patents

Abstract

PURPOSE: To read out depth of screw by means of a torque measuring machine measuring fastening torque when a bolt is fastened into a screw hole. CONSTITUTION: When a bolt is fastened into a screw hole, a time (X-Y) from a time X at contacting threaded parts of a screw hole and the bolt with each other so as to raise a torque value to a time Y at suddenly changing the torque value is measured, and a number of revolution during that time is obtained, for example, at Y-X=t(sec), the number of revolution is t×R/60 (revolution). This is multiplied by a pitch (p) of the screw hole, and hence depth of the screw is obtained. Sudden change of the torque value is a sudden decrease in the case of a through hole, and a sudden rise in the case of a blind hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading method and device for simultaneously reading a tightening torque and a screw depth by a torque measuring machine when a tightening bolt is screwed into a screw hole.

[0002]

2. Description of the Related Art Conventionally, as a measuring device for measuring the depth of a screw hole, for example, Japanese Utility Model Laid-Open No. 55-127208, Japanese Utility Model Laid-Open No. 61-197503, or Japanese Unexamined Patent Publication No. 1-174901.
Techniques such as the issue are known. And the above-mentioned actual development 5
In the case of No. 5-127208, a measuring bolt with a graduated screw part is screwed into the screw hole, and the graduation is read to know the screw depth.
In the case of No. 03, a probe equipped with light emitting and light receiving means is inserted into a screw hole, and the screw depth is measured by irradiating and moving the screw sliding surface with light. Further, in the case of JP-A-1-174901, a rotary encoder is provided in the housing, and the screw depth is digitally displayed by rotation of a screw gauge screwed into the screw hole.

[0003]

However, these are all dedicated jigs for measuring the screw depth. For example, after measuring the screw depth, it is attempted to measure the tightening torque when tightening the bolt. Then, it was necessary to use two devices, the screw depth measuring device and the torque measuring device. Also,
Among the above-mentioned screw depth measuring devices, particularly, the actual screw-opening Sho 61-1975
In the case of No. 03 or Japanese Patent Application Laid-Open No. 1-174901, there is a problem that a complicated structure and a precise mechanism are adopted, and a complicated procedure is required for handling.

[0004]

In order to solve the above problems, the present invention is designed to read the screw hole depth by a torque measuring machine for measuring the tightening torque of a tightening bolt.
That is, when the screw hole is in the shape of a bag, the time from the time when the tightening bolt and the threaded portion of the screw hole contact each other to increase the torque value to the time when the stable torque value sharply increases is measured. The thread depth was read from the relationship between time and the pitch of the screw holes.

When the screw hole is a through hole, the time from when the tightening bolt and the screw portion of the screw hole contact each other to increase the torque value to when the stable torque value sharply decreases is measured. Then, the thread depth was read from the relationship between this time and the pitch of the screw holes.

As a device for reading the screw hole, a torque measuring device for measuring the tightening torque when the tightening bolt is screwed into the screw hole, and the torque of the tightening bolt and the screw portion of the screw hole are in contact with each other. Calculate the time from the time when the value rises to the time when the stable torque value changes abruptly, and calculate the thread depth from the relationship between this time and the pitch of the screw hole, and display means that displays this result. Provided.

[0007]

[Operation] When the tightening bolt is screwed into the screw hole, the torque value rises to a predetermined torque value from the time when the tightening bolt and the threaded portion of the screw hole contact each other. During tightening, the tightening torque is stable at a constant value. When the screw hole is a blind hole, the torque value sharply increases when the tightening bolt is screwed to the deepest part of the screw hole and cannot move further. Therefore, if the time during which the tightening bolt was screwed was measured by measuring the time during which the tightening bolt was screwed in, the number of rotations required for the tightening bolt to be screwed in was calculated from this time. Multiply the pitch of the screw holes to find the screw depth.

Further, when the screw hole is a through hole, the torque value sharply decreases when the tightening bolt penetrates the screw hole. Therefore, similarly to the above, the time required to stabilize at a constant torque value is measured to obtain the number of revolutions required for the tightening bolt to be screwed in, and the number of revolutions is multiplied by the pitch of the screw hole to obtain the screw depth. .

[0009]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a schematic view of a torque measuring machine, (A) is a plan view, (B) is a side view, FIG. 2 is an example view of tightening torque measurement values of through-holes, and FIG. 3 is a bag. It is an example of a tightening torque measurement value of a screw hole.

As shown in FIG. 1, the torque measuring machine 1 can measure the tightening torque when tightening the tightening bolt B in the screw hole Wh of the work W positioned on the base 2. The table 4 which is movable back and forth with low friction along the guide member 3, the torque sensor built-in drive unit 6 attached to the column 5 rising from the table 4, and the torque sensor built-in drive unit 6 are connected to the cup. It comprises a holder 8 connected via a ring 7. The holder 8 is adapted to hold the base end side of the tightening bolt B.

Then, the tightening bolt B is attached to the holder 6, and while driving the torque sensor built-in type driving portion 6, the table 4 is stroke-moved in accordance with the lead of the screw,
Measure the tightening torque. Incidentally, although the screw hole Wh of the work W in FIG. 1 is a bag-shaped screw hole, it can be applied to torque measurement of a through-hole screw hole.

Therefore, the result of measuring the tightening torque of the through screw hole by using the above torque measuring machine 1 will be described with reference to FIG. Here, in FIG. 2, the horizontal axis represents time (se
c) shows the torque value (kg / cm) and the rotation speed (rpm) on the vertical axis, the solid line shows the torque value, and the broken line shows the rotation speed. According to this example, the rotation speed of the driven tightening bolt B is R rpm, and the tightening torque value is approximately Qkg / c from the time point X when the tightening bolt B and the threaded portions of the screw holes contact each other.
The torque value stabilizes at around m, and the torque value sharply decreases at the time Y when the tightening bolt B penetrates the screw hole and there is no resistance.

Therefore, a method of reading the screw depth of the screw hole from the above torque value will be described. Time that the tightening bolt B is screwed into the screw hole (Y-X)
From this, the number of revolutions of the tightening bolt B while screwed in can be known.
For example, if Y−X = t (sec), the rotation speed is t × R /
It becomes 60 rotations. Therefore, if the pitch of the screw holes is, for example, p (mm), the screw depth is p × t × R / 60 (m
m).

Next, FIG. 3 shows an example of the torque value of the bag-shaped screw hole. In this case, the torque value sharply increases at the time Y when the tightening bolt B is screwed in to the end, but the time during which the tightening bolt B is screwed into the screw hole (Y-X).
The procedure for obtaining the thread depth from is the same as the above procedure. Incidentally, when the tightening bolt B is screwed into the bag-shaped screw hole, the torque sensor built-in drive unit 6 is stopped at the time Y when the torque value sharply rises, or the rotation is stopped, or the clutch is rotated. The mechanism prevents transmission of the rotational driving force to the tightening bolt B, thereby preventing overload.

The reading method of the present invention is performed in the above-described procedure, but as the apparatus configuration, the torque measuring machine is connected to a computing means and a display means (not shown). This calculation means
The time (Y-X) in which the tightening bolt B is screwed in is measured, and the number of revolutions of the tightening bolt B in the meantime is obtained,
This rotational speed is multiplied by the pitch of the screw holes to perform arithmetic processing, and the display means displays the result in analog or digital form.

[0016]

As described above, according to the present invention, since the screw depth of the bag-shaped or penetrating screw hole is read by the torque measuring machine for measuring the tightening torque, the torque value is measured and the screw depth is measured. Can be measured at the same time, and the trouble of using two dedicated jigs as in the conventional case can be saved. Moreover, the equipment structure is simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a schematic view of a torque measuring machine, (A) is a plan view,
(B) is a side view

FIG. 2 is a diagram showing an example of measured tightening torque of a through-hole screw hole.

FIG. 3 is a diagram showing an example of measured tightening torque of a bag-shaped screw hole.

[Explanation of symbols]

 1 ... Torque measuring machine, B ... Tightening bolt, Wh ... Screw hole.

Claims (3)

[Claims] 1. A reading method in which the thread depth of a bag-shaped screw hole is read by a torque measuring machine for measuring the tightening torque, and the tightening bolt and the threaded portion of the threaded hole are in contact with each other, and the torque value is Measuring the time from the time of rising to the time when the stable torque value suddenly rises, and reading the screw depth from the relationship between this time and the pitch of the screw hole. Method. 2. A reading method in which the thread depth of a penetrating threaded hole is read by a torque measuring machine for measuring the tightening torque, and the tightening bolt and the threaded portion of the threaded hole contact each other and the torque value is Measuring the time from the point of rise to the point where the stable torque value sharply decreases, and reading the screw depth from the relationship between this time and the pitch of the screw hole. Method. 3. A torque measuring device for measuring a tightening torque when a tightening bolt is screwed into a screw hole, and from a point of time when the tightening bolt and the threaded portion of the screw hole come into contact with each other to increase the torque value. The present invention is characterized by including a calculating means for calculating a time until a stable torque value changes abruptly and calculating a screw depth from a relationship between this time and a pitch of a screw hole, and a displaying means for displaying the result. A device for reading the screw depth.