JPH02293610A - Detector for unworking of internal thread - Google Patents

Abstract

PURPOSE:To eliminate the influence of chip and cutting fluid and to inexpensively and surely detect the unworking of threads by providing an air supply hole in the central part of a measuring element, inserting the measuring element into the threaded hole to be inspected, then supplying compressed air and detecting a back pressure. CONSTITUTION:The air supply hole is provided to the center of the measuring element 1 which can be freely inserted into the hole 10 to be inspected and after the element is inserted into the threaded hole 10a to be inspected, the compressed air is supplied. Just a small volume of the air merely flows out of a tapered part 2 in the case of an unworked product (defective product) 11b of the internal threads but the air flows out of screw threads to the outside in the case of the product 11a worked with the internal threads. The back pressure of the supply air is, therefore, larger with the defective product 11b. A detecting section detects a large pressure and emits an unworking detection signal. Since the air is ejected at the time of the insertion, the chip, etc., are cleaned and the inexpensive and sure inspection is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device for detecting defects in female thread machining (female thread machining omission) in a product whose pilot hole is to be machined with a female thread.

[Conventional technology]

For products that have a female thread machining process, if the female thread is sent to a subsequent process or shipped with the female thread unprocessed, it will not be possible to assemble or install it, causing great confusion. It is necessary to discover defects in female threads. For this purpose, conventional visual inspections by workers or inspections using proximity switch-type tap sensors or laser light have been carried out. This increases the man-hours of the person and the running cost.

In addition, in the case of an intruder, it is difficult to carry out the process immediately after the internal thread machining process because it is susceptible to the attack of chips and cutting oil and reduces reliability.

[Problem to be solved by the invention]

The present invention is intended to solve the above-mentioned conventional problems, and aims to provide an unprocessed female thread detection device that can reliably detect unprocessed defects at low cost.

[Means to solve the problem]

The present invention will be explained below based on the drawings.

FIG. 1 is a diagram illustrating the basic concept of the present invention. An air supply section 30 that supplies compressed air into the air supply hole 4 of the probe 1; When the back pressure of the compressed air supplied into the air supply hole 4 is detected and this detected pressure is greater than the set value (in the case of the first invention), or the flow rate of the compressed air supplied into the air supply hole 4. is detected and this detected flow rate is smaller than the set value (in the case of the second invention)
, and a detection section 40 that generates a raw detection signal.

(Operation) In the device of the present invention, as shown in FIG. When the air supply unit 30 supplies compressed air to the air supply hole 4, this compressed air is blown into the hole 10 to be inspected. In the case of the product (good product) 11a, it flows out through the spiral thread groove of the female thread 12, whereas the product with an unprocessed female thread
In the case of defective product》11b, only a small amount of air flows out from the minute gap between the tapered part 2 and the opening end of the hole 10 to be inspected, so the back pressure of the air supplied to the air supply hole 4《 The pressure inside the hole 1o to be inspected is larger in the latter case than in the former case, and the flow rate of the air (air outflow tooth from the hole 10 to be inspected) is smaller in the latter case than in the former case.

In the first invention, by using the intermediate value of the back pressure in the above two cases as the set value of the detection unit, the detection unit detects a pressure greater than the set value for the unprocessed threaded product, and the detection unit detects the unprocessed product. emit a signal. In addition, in the second invention, by using the intermediate value of the flow rate in the above two cases as the set value of the detection section, the detection section detects a flow rate smaller than the set value for unprocessed threaded products, and the detection section detects the unprocessed product. A signal is emitted and the unprocessed product is detected.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 to 5.

In FIGS. 2 and 3, reference numeral 1 denotes a probe, and the portion that contacts the open end of the hole 10 to be inspected has a tapered portion 2 of approximately 5°.
The distal end portion 3 is further chamfered by 15° to facilitate insertion, and the lower end of the air supply hole 4 provided inside is connected to the end surface 3a&:IFI of the distal end ts3. This probe 1 is made of SKD11 material in consideration of durability, and its right cylindrical portion 5 has a pusher 7 fixed to a holder 6.
It is supported so as to be able to slide vertically with a slight gap between the two sides, and is biased downward by a spring 8 within the holder 6. The holder 6 is fixed to a piston rod of an air cylinder 20 for vertical driving, and this air cylinder 20 is attached to a support 22 erected on a jig 21 on which a product 11 to be inspected is placed.
It is fixed to via a bracket 23. Reference numeral 30 denotes an air supply section, which serves not only for supplying compressed air for detection but also for driving the air cylinder 20 and for air blowing.
The pressure is reduced to IKl/d and supplied to the cylinder drive solenoid valve 24 and the air blow solenoid valve 25. On the other hand, the pressure is reduced to IKl/d by the pressure reducing valve 34 via the mist separator 33, and the flow rate adjustment valve 35 for adjusting measurement accuracy and the detection Compressed air is supplied to the probe 1 via the operating solenoid valve 36. Note that the air flow adjustment valve 35 is adjusted so that the discharge i%El of the compressed air becomes INJ/Pengin in the air-open state where the probe 1 is not inserted into the hole 1o to be measured. Further, 40 is a detection unit, 41 is a pressure switch, and the pressure adjustment screw is set so that the contact closes at a pressure of 0.4 phantom/d, and 42 is a back pressure display used during this adjustment. 43 is a detection port path that detects the opening and closing of the pressure switch 41 and issues a raw detection signal, and 44 and 45 are an abnormality lamp and a buzzer operated by this signal. Further, 26 and 27 are flow control valves for adjusting the speed of the air cylinder 20, and 28 is an exhaust cleaner.

Next, the operation of the apparatus having the above configuration will be explained with reference also to FIG. First, the product 11 to be inspected is placed in the jig 21.
If the start switch, which is attached manually and is not activated by hand, is closed for a short period of time, the cylinder drive solenoid valve 24 and the air blow solenoid valve 25 are energized for a short period of time 1+, and the air cylinder 20 is activated for forward drive I7l ( As the piston rod is driven to protrude, air is ejected downward from the air supply hole 4 of the probe 1. As a result, the probe 1
falls and rises to clean the inside of the hole 10 to be inspected with the jet of air to remove chips and the like, and the taper portion 2 of the probe 1 is pressed against the open end of the hole 10 to be inspected. It is carried out. At this time, the spring 8 causes the probe 1 and the product 1 to
It is possible to prevent damage caused by the collision described in item 1. Next, after time t2, the air cylinder 20 is driven forward again, and re-cleaning is performed by air jetting from the probe 1 during time t3, and after time t4, the electromagnetic valve 36 for detection operation is energized. Compressed air of 1 kg/ci for detection is supplied to the probe 1 and blown into the hole 10 to be inspected. After time t5, if a voltage is applied to the terminal of the pressure switch 41 by the detection circuit 43 and a determination is made, the product 11 has a female thread 12 machined in the hole 10 to be inspected.
In case a, the back pressure is O due to air flowing out through the female thread 12. 4 Kfl/i, the pressure switch 41 remains open, and upon this OK detection, the air cylinder 20 retreats and the inspection ends. In addition, in the case of the product 11b in which the inspected hole 10 is not internally threaded, the back pressure is close to lg/1 (0.4 KI/ ai or more'', the pressure switch 41 is triggered and the detection circuit 43 issues a raw detection signal @NG. This signal causes the abnormality lamp 44 to light up and the buzzer 45 to sound. The occurrence of a processed product can be detected.The above-mentioned times t1 to 15 are set by a timer in the detection circuit 43.

In this embodiment, prior to detecting an unprocessed female thread, the inside of the hole 10 to be inspected is cleaned using compressed air with a higher pressure than that for detection, which is ejected from the tip of the probe 1 through the air supply hole 4. Therefore, even immediately after the female thread machining process, unmachined parts can be reliably detected without being affected by chips or the like, which is particularly preferable. Furthermore, prior to detecting an unprocessed female thread, the taper portion 2 is pressed against the open end of the hole 10 to be inspected to perform contact.
In particular, it is possible to accurately detect unprocessed parts for products made of soft materials such as aluminum.

Using the device with the above configuration, ADCI 2A product 11
M6P1.
We prepared 42 pieces with 12 female threads machined and 37 tin pieces without machined female threads, and directly detected the unprocessed parts by omitting the above-mentioned abutment. The reading value of 42> was distributed as shown in FIG. 5, and it was possible to correctly detect the unprocessed products for all the unprocessed products.

The above description has been made on the case where the hole 10 to be inspected is a blind hole, but if the hole 10 to be inspected is a through hole as shown in FIG. The unprocessed state can be detected in the same manner as described above with the opening closed by pressing the sealing material 13 such as urethane rubber.

The present invention is not limited to the above-mentioned embodiments. For example, the air supply unit 30 supplies low-pressure, clean air when the air valve O- and the air cylinder 20 are also driven.
can be made more compact by omitting the pressure reducing valve 32 and the mist separator 33. In addition, the detection unit 40 converts the back pressure into voltage using a piezoelectric conversion element and determines whether it is unprocessed by comparing it with a reference voltage corresponding to a set value.
It is also possible to have a configuration other than the above. Furthermore, the detection unit 40
The compressed air flow rate at the outlet of the flow rate adjustment valve 35 or the detection operation electromagnetic valve 36 is detected and compared with the set flow m value, or it is configured to emit not only a raw detection signal but also a processed detection signal. The normal lamp may be turned on based on this detection signal. Also, as the measuring head 1,
Various shapes can be used, such as one in which the tapered part 2 and the tip part 3 have the same taper as shown in FIG. I can do it. Furthermore, the support structure and drive structure of the measuring element 1 may be other than those described above, and the measuring element 1 may be kept stationary while the product 11 is moved up and down.

(Effects of the Invention) As explained above, according to the present invention, since compressed air is used for detection, it is less susceptible to the effects of chips and cutting fluid, and it is possible to accurately detect unprocessed parts even in the subsequent process of thread machining. Furthermore, the probe is small and can be easily installed in existing equipment, and the detection device has a simple structure, is economical, and has excellent durability.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the principle of this invention, Fig. 2 is an equipment system diagram showing an embodiment of this invention, Fig. 3 is a vertical cross-sectional view of the probe portion of Fig. 2, and Fig. 4 is a sequence diagram of the device shown in FIG. 2, FIG. 5 is a histogram showing inspection data by the device shown in FIG. 2, FIG. FIG. 8 is a longitudinal cross-sectional view of a main part showing another embodiment of the probe.

Claims (1)

[Claims of Claims] 1. A measuring element having a tip that can be inserted into and removed from a hole to be inspected, a tapered portion that engages with an open end of the hole to be inspected, and an air supply hole that opens in the tip. , an air supply section that supplies compressed air into the air supply hole of this probe, and detects the back pressure of the compressed air supplied into the air supply hole, and when this detected pressure is greater than a set value, unprocessed detection is performed. A detection device for detecting unprocessed female threads, comprising a detection section that emits a signal. 2. A probe having a tip that can be inserted into and removed from a hole to be inspected, a tapered portion that engages with the open end of the hole to be inspected, and an air supply hole that opens in the tip; an air supply section that supplies compressed air into the air supply hole; and a detection section that detects the flow rate of the compressed air supplied into the air supply hole and issues a raw detection signal when the detected flow rate is smaller than a set value. A female thread unprocessed detection device comprising: