JPS649897B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention provides a method for rolling threads when thread rolling machines such as flat die rolling machines and segment rolling machines equipped with fixed dies and movable dies. This invention relates to a device that detects slippage defects that occur during manufacturing.

(b) Prior art When a screw is rolled using a flat die rolling machine, etc., during the rolling process, the screw held between the fixed die and the movable die is lifted up during rolling and is not rolled correctly. Screw defects may occur due to incorrect rolling due to the so-called slippage phenomenon in which the ejecting position of the screw that has completed rolling changes due to the rolling length of the screw becoming longer or shorter. .

For example, there is a device proposed in Japanese Patent Publication No. 40502/1983 to deal with screw defects due to the former phenomenon of lifting.

However, no effective proposal has been made up to now as a device for detecting screw defects due to the latter slipping phenomenon.

(c) Purpose of the Invention Therefore, the present application provides a device for detecting screw defects due to the slippage phenomenon, and improves productivity by linking the device with a device etc. that sequentially removes screws with non-slipness detected by the device. The aim is to contribute to improving quality and ensuring quality.

(d) Background of the Invention The concept of slip detection, which is the background of the present application, will be explained.

FIG. 1 is an explanatory diagram showing a rolling state during one rolling cycle of a crank mechanism connected to a movable die, and FIG. 2 is an explanatory diagram showing the relationship between a fixed die and a movable die. The movable die linked to the crank mechanism moves toward the fixed die until the crankshaft rotates 180 degrees. During this time, the movable die and the fixed die grip the screw material and bite into the specified screw. After rolling, the rolling screw is ejected, and after turning 180 degrees, it moves back away from the fixed die. The rolling length of the screw on the fixed die from the biting position to the discharge position is Ls, and the rolling length of the screw on the movable die is Lm. When rolling is performed normally without any slipping phenomenon, Lm=Ls, and the ejection position of the screw on the moving die is constant. Therefore, by setting an appropriate screw ejection position on the movable die in advance and checking the presence or absence of the screw at the set ejection position, it is possible to determine whether or not slippage has occurred.

For example, if a slippage of X mm occurs on the fixed die side, the rolling length of the screw on the movable die is Ls'=Lm-X, and Lm>Lm'. Also, if a slippage of Ymm occurs on the moving die side, the rolling length of the screw on the moving die Lm' =
Lm+y, so Lm<Lm'.

In any case, Lm = Lm' = Ls only when rolled normally. However, in actual rolling, it is difficult to achieve a perfect match, so a certain tolerance is set and those discharged within this range are considered non-defective.

(E) Structure of the Invention The gist of the present application is to provide a thread rolling machine that rolls a thread material held between the fixed die and the movable die while linearly reciprocating or rotationally moving the movable die relative to the fixed die. A screw slippage defect detection device is provided, which detects the discharge position of the thread material and determines whether the thread material has been rolled or not, and when the thread material that has been rolled reaches the permissible discharge position, A voltage is applied between the position setting means that generates position setting pulses at the upper and lower limits of the allowable range, the fixed die and the movable die, and a voltage is applied between the fixed die and the movable die to set the value to ``1'' or ``0'' depending on the presence or absence of the clamped screw material. The screw detection means generates a rectangular-wave screw detection pulse whose potential is changed to a binary signal of Screw slippage defect detection device consisting of a comparative judgment control circuit that determines whether or not the potential change point of the screw detection pulse occurs while the next position setting pulse is input. It is.

(F) Embodiment Figure 3 shows a plan view of the mechanical part of the device of the present application.
The configuration of each part is as follows.

A drive pinion gear 1 that rotates under drive from a drive source (not shown), a crank gear 2 that rotates following the drive pinion gear 1, and a connecting rod 3 that is eccentrically connected at one end to the crank gear 2. , a movable die 4 that is swingably connected to the other end of the connecting rod 3 and that performs reciprocating motion by rotation of the crank gear 2;
a movable die 5 mounted on the movable die 5, a die presser 6 that fixes the movable die 5 to the movable die 4, and a ram presser 7 that guides the movable die 4 during reciprocation.
, a fixed die 8 arranged opposite to the movable die 5, a fixed die 9 to which the fixed die 8 is attached, a die holder 10 for fixing the fixed die 8 to the fixed die 9, and a die holder 10 for fixing the fixed die 8 to the fixed die 9; The guide rail 12 feeds the screw material 11 between the fixed die 8 and the fixed die 8, and the screw presser 13 prevents the fed screw material 11 from escaping. However, each of the above configurations has been conventionally used.

Next, as a configuration unique to the present application, a rotating shaft 14a of a potentiometer 14 fixed to the main body (not shown) is connected to the center shaft 2a of the crank gear 2, and the potentiometer 14 is connected via a lead wire 15. It is connected to a control circuit that will be described later.

Further, an insulator 16 is interposed between the fixed die 8 and the fixed die 9, and a terminal 17 is provided on the fixed die 8, and the terminal 17 is connected to a control circuit to be described later through a lead wire 18.

It goes without saying that an insulator may be interposed on the moving die side.

Furthermore, a terminal 19 is also provided on, for example, the ram presser 7 which is electrically at the same potential as the moving die 5, and the terminal 19 is connected to a control circuit to be described later through a lead wire 20. The potentiometer 14
DC12V is supplied from the control circuit to the fixed terminal of
When the rotating shaft 14a is rotated by the rotation of the crank gear 2, a variable voltage of 0 to 12 V is taken out to the sliding terminal, and this voltage is returned to the control circuit. This variable voltage generates a sawtooth wave as shown in the waveform diagram 1 shown in Figure 5, and sets the first setting position T ₁ and second setting position T ₂ , which are set at the upper and lower limits of the discharge range allowable for the screw. This is to obtain from the voltage V ₁ and the set voltage V ₂ .

On the other hand, DC 12V is supplied to the fixed die 17 via the lead wire 18, and a potential difference of 12V is generated between the fixed die 18 and the movable die 5, and the screw material 11 is inserted between the two dies. When clamped, the potential is reduced to 0 via the screw material. Therefore, depending on the presence or absence of the screw material 11, the voltage is 12V (H) as shown in waveform 3 in Figure 5.
Or generate a 0V (L) square wave.

Next, the control circuit will be explained based on the block diagram of FIG. 4 and the waveform diagram of FIG. 5.

As described above, the screw detection unit 21 receives +12V from the DC power supply 22 and detects the presence or absence of the screw material 11 based on the 12V or OV screw detection pulse _P0 taken out from the terminal 17.
If there is, L (OV), if not, H (12V)
Output each. The position setting unit 23 receives the set voltages V ₁ and V ₂ of the potentiometer 14, and sets the upper and lower limits T ₁ ,
At T ₂ , position setting pulse P ₁ , as shown in waveform 2 in Figure 5,
P ₂ respectively. Screw detection part 2
1 and each output of the position setting section 23 are sent to a comparison circuit 24. The comparator circuit 24 detects the presence or absence of the screw material 11 at the first and second setting positions T ₁ and T ₂ , and the screw detection pulse P ₀ is inverted by the inverter INV-1 and then , AND circuit that performs detection at the first set position _T1
It is directly transmitted without going through an inverter as one input of AND-1 and as one input of AND circuit AND-2 which performs detection at the second set position _T2 .

Further, the position setting pulse P ₁ supporting the first setting position T ₁ is used as the other input of the AND circuit AND-1 as a position setting pulse indicating the second setting position T ₂ .
_P2 is transmitted as the other input of the AND circuit AND-2.

The judgment circuit 25 receives each comparison result from the comparison circuit 24 and judges whether the rolled screw material 11 is a good product or a defective product.

The output of the AND circuit AND-1 is mono multi
The AND output is transmitted to the MM, but if there is a thread material at the first setting position T ₁ , it is assumed to be OK and output H is generated, and the mono-multi MM is operated to compare at least the second setting position T ₂ . Until the result arrives, the output H is transmitted as one input of the AND circuit AND-3. The output of the AND circuit AND-2 is transmitted as the other force of the AND circuit AND-3, but this AND output is based on the case where the screw material 11 is not discharged within the allowable range at the second setting position _T2 .
As 0K, a pass pulse as shown in waveform 4 in FIG. 5 is generated, which is transmitted to the production counter 26 and counted as a good product.

Further, the inverter INV-2 in the discrimination circuit 25 inverts the position setting pulse _P2 from the position setting section 23 and transmits it to one input of the NOR circuit NOR, and the NOR circuit NOR is connected to the AND circuit AND-3. Defective products are determined using the output as the other input.

In other words, the NOR circuit generates an output H only when the input is L-L, and the pass pulse H
is applied to the other input, it will not operate, and if the screw is ejected earlier or later than the allowable range as shown in the waveform diagram 3 in Fig. 5, the screw detection pulse will be set at the first and second set positions T ₁ and T. ₂ , it becomes LL or HH, and in this case, a fail pulse is generated. This reject pulse is sent to the defective product ejection device 2.
7, and the defective rolling screw is removed by the device.

6A to 6F are for explaining the operating states of the control circuit, and FIGS. 6A and 6B are waveform diagrams 3 of FIG. 5.
This is an explanatory diagram when a passing product is rolled, with a screw at the setting position T ₁ and no screw at the setting position T ₂ , as in the first time in .

In Fig. 6 C and D, there are no screws in both setting positions T ₁ and T ₂ as in the second waveform diagram 3 in Fig. 5.
It is an explanatory view when a rejected product is rolled.

In Fig. 6 E and F, as in the third waveform diagram 3 in Fig. 5, both setting positions T ₁ and T ₂ have screws,
It is an explanatory view when a rejected product is rolled.

In this way, it is confirmed that the thread rolling work is performed on the thread material 11 up to the first set position _T1 , and that it is discharged at the second set position _T2 ,
Items that meet this condition are determined to be non-defective because the slippage is within an allowable range, and items that meet other conditions are determined to be defective.

(g) Effects of the invention As is clear from the above embodiments, the quality of rolled screws due to the sliding phenomenon can be sequentially determined by simply checking the presence or absence of screw material at two arbitrarily set positions, and defective products can be eliminated. Necessary measures such as these can be taken, and these operations can be carried out without any hindrance to the rolling process for mass production.

Therefore, it is an extremely effective slippage detection device for improving productivity and ensuring quality.

Incidentally, the present application is not limited to the above embodiments, and various modifications can be made within the scope of the gist. For example, the position detection by the potentiometer in the above embodiment may be performed using a rotary encoder or the like, or a limit switch or other sensor may be provided on the path of the movable dice to perform the position detection.

Furthermore, it goes without saying that a control circuit that receives pulses from the screw detection section and the position setting section and compares and determines whether the screw is good or bad can be selected from known electric circuits that perform the same function.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the rolling state in one rotoring cycle, Fig. 2 is an explanatory diagram showing the relationship between fixed dies and movable dies, Fig. 3 is a plan view showing the mechanism part, and Fig. 4 is a control circuit. Block diagram, No. 5
The figure is a waveform diagram of a control signal, and FIGS. 6A to 6F are diagrams explaining the operation of the control circuit. [Explanation of symbols], 1... Drive pinion gear,
2...Crank gear, 3...Conrod, 4...
Moving die, 5...Moving die, 6, 10...Dice holder, 7...Ram holder, 8...Fixed die, 9
... Fixed die, 11 ... Screw material, 12 ... Guide rail, 13 ... Screw holder, 14 ... Potentiometer, 15, 18, 20 ... Lead wire, 16
... Insulator, 17, 19 ... Terminal, 21 ... Screw detection section, 22 ... DC power supply, 23 ... Position setting section,
24...Comparison circuit, 25...Discrimination circuit, 26...
Production counter, 27...defective product discharge device.

Claims (1)

[Scope of Claims] 1. A thread rolling machine that rolls a thread material held between the fixed die and the movable die while linearly reciprocating or rotationally moving the movable die with respect to the fixed die; This is a screw slippage defect detection device that detects the discharge position of the material and determines whether the thread material has been successfully rolled.When the rolled thread material reaches the permissible discharge position, A voltage is applied between the fixed die and the movable die, and a binary value of "1" or "0" is determined depending on the presence or absence of the clamped screw material. The screw detecting means generates a rectangular wave screw detecting pulse whose potential is changed in the signal, and compares the input position setting pulse and the screw detecting pulse, and determines the first position setting pulse and the next position setting pulse. A screw slippage defect detection device comprising a control circuit for comparison and determination that determines whether or not the discharge position of the screw material is good or not based on whether or not a potential change point of the screw detection pulse occurs while the pulse is input.