JPS6116543B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for simultaneously tightening a plurality of rivets, and more particularly to a rivet tightening device equipped with a rivet presence/absence detecting device that utilizes the time difference between the times at which each rivet starts tightening. .

Generally, when tightening rivets such as bearing retainers, a plurality of rivets are tightened at the same time, and the number of rivets is inspected and confirmed in a separate process after tightening is completed. Inspection and confirmation of the number of rivets (hereinafter referred to as the presence or absence of rivets) was done visually or by checking with a direct switch, which required a separate detection device independent of the rivet tightening device. There were problems with equipment and man-hours.

The present invention has been made in view of the above-mentioned conventional problems, and provides a rivet presence/absence detection device using a direct contact synchronized time difference method. below,
The structure of the present invention will be described with reference to the drawings, taking as an example the tightening of a bearing retainer.

In Fig. 1, 1 is a fixed base in the riveting device, 2 is a lower die attached to the fixed base 1 via a spring 3, and 4 is an upper die that moves up and down above the lower die 2. be. Further, in FIG. 2, reference numeral 5 indicates a rivet, and 6 indicates a retainer that is joined by the rivets 5. The retainer 6 is placed on the lower die 2 and is joined by crimping a required number of rivets 5. This rivet 5 is tightened using the upper mold 4 and a punch pin 7, which will be described later.

That is, the punch pin 7 is fitted into through holes 2' and 1' provided in the lower die 2 and the fixed base 1, respectively, and is normally supported by a spring 8 with a gap m between it and the fixed base 1. Then, the punch pin 7 is pressed by the rivet 5 at the time of crimping the rivet, moves down by this distance m and stops, and from that point on, crimping of the rivet 5 starts. Further, the upper end of the punch pin 7 and the lower ends of the rivet 5 and retainer 6 have intervals n and l (see FIG. 2).

In the above configuration, the presence or absence of the stud 5 is detected by the direct switch 9, its conductor 10, and the electric control section 11. That is, the direct switch 9 is fixed to the fixed base 1 via the insulating support plate 12, and the conductor 10 is fixed to the lower end of the punch pin 7. The two are normally in contact with each other, and when the punch pin 7 is lowered, they are separated and become insulated. In other words, the direct switch 9 detects when the punch pin 7 starts descending, and whether the descending timing is late or not.
The electric control unit 11 detects whether the stud 5 is fast or not, thereby detecting the presence or absence of the stud 5. This is an application of the so-called direct contact synchronous time difference method, and its operation is as follows. Incidentally, the direct switch 9, the conductor 10, and the punch pin 7 are arranged as one set for one stud 5.

First, the operation of the above structure will be explained only with respect to the part where the stud 5 is present, as shown in FIGS. 2 to 5. That is, as shown in FIG. 2, the studs 5 are normally set in the retainer 6. In this state, the upper mold 4 is lowered. Then, the upper mold 4 first hits the retainer 6, then presses the lower mold 2, and the lower mold 2 descends against the spring 3. When it has descended by a distance n, the lower end of the stud 5 touches the upper end of the punch pin 7. Hit. This is the state shown in FIG. 3, and when the upper mold 4 is further lowered in this state, the punch pin 7 is pressed through the rivet 5 and starts to lower from this point. At the moment when the punch pin 7 descends,
Each direct switch 9 is separated and becomes insulated. Then, when the punch pin 7 descends by a distance m, it hits the fixed base 1 and stops there. In other words, the state shown in Fig. 4 is reached, and when the upper mold 4 is further lowered in this state, the studs 5 are vertically compressed by the upper mold 4 and the punch pin 7, as shown in Fig. 5, and the crimping is completed. . Thereafter, when the upper mold 4 is raised, the lower mold 2 and the punch pin 7 are returned to their original positions by the respective springs 3 and 8.

Next, the operation without the stud 5 will be described. In this case, the process will be as shown in FIGS. 6 to 8. In other words, when the upper mold 4 descends, hits the retainer 6, and further descends by a distance n, the state becomes as shown in FIG. At this time, retainer 6 and punch pin 7
has an interval of (l-n). Then, when the upper mold 4 further descends by (l-n), the retainer 6 hits the punch pin 7 as shown in FIG. Switch 9 becomes insulated. That is, the point in time when the punch pin 7 descends occurs when the upper mold 4 has descended by a distance l after it hits the retainer 6.

In this way, the electric control unit 11 detects and controls the time difference that occurs when the punch pin 7 descends depending on the presence or absence of the rivet 5 to determine and display the presence or absence of the rivet. Due to positional deviations, etc., all the studs 5 do not necessarily press and lower each punch pin 7 at the same time, and there may be a slight time lag in the lowering timing of the punch pin 7. The configuration is such that it can be detected by determining whether or not the "stack present" signal is output for all the rivets within a predetermined time after the th "stack present" signal is output.

Next, the operation of the electric control section 11 will be explained based on FIG. 9.

The number of direct switches (DMS) between the fixing base 1 and the punch pins 7 is equal to the number of punch pins 7, that is, the number of rivets, and the output signal of each DMS is inputted to a (NOT) circuit 21 and a (NAND) circuit 22. In this (NOT) circuit 21, the first OFF output out of the N (DMS) is sent from the (NAND) circuit 23 to the memory circuit FF-1 via the differential element, and is used as the input signal of the timer _T1 . . The time of the timer _T1 is used to set the time for the rivet to finish tightening, that is, the grace period for FF-2 to output the abnormality signal _S1 . Also, the (NAND) circuit 22 is N
A reset signal is given to the memory circuit FF-1 via the (NOT) circuit 24 by all the OFF output signals of the (DMS). Therefore, when one or more studs are missing, the reset signal is not given from the (NAND) circuit 22 to the memory circuit FF-1 via the (NOT) circuit 24, so the grace period _T1 is set up and the abnormality signal S is generated. ₁ comes out. On the other hand, when all the studs are present, the normal signal S 2 is sent from the memory circuit FF-3 via the (NAND) circuit 23 to the (NOT) circuit 25, waits for the timer 26 to finish tightening the studs, and then outputs the normal signal S ₂ from the memory circuit FF-3.
will appear and be confirmed.

As explained above, the present invention is a device for simultaneously tightening multiple rivets such as a bearing retainer, which includes a fixed base, a fixed base that can be raised and lowered for more than the rivet stroke of the rivets, and is constantly raised by a spring. A lower mold is elastically held at an end position, has a retainer mounting surface at its upper end, and has vertical through holes corresponding to each stud position, and is inserted into each of the through holes of the lower mold so as to be freely raised and lowered. ,
It has a recess for crimping the rivets on its upper surface, and when the rivets are crimped, they can be raised and lowered individually via the rivets, and are always elastically held at the rising end position by a spring with a lower elasticity than the spring of the lower mold, In addition, when tightening the rivet, the rivet is lowered in advance of the lower die and is stopped in contact with the fixed base, and the upper surface at the rising end position is
A plurality of punch pins are positioned below the retainer mounting surface at the rising end position of the lower die, and a top plate corresponding to the punch pins is provided above the lower die so as to be able to move up and down by more than the crimping stroke of the stud. Since it is composed of a mold and a detector installed between each of the punch pins and the fixing base to individually detect the relative displacement of each punch pin in the vertical direction with respect to the fixing base, when tightening the rivets,
The presence or absence of rivets can be confirmed by using the difference in the timing at which each punch pin starts descending, and the presence or absence of rivets can be detected in the same process as the rivet tightening process. is downsized. Further, the presence or absence of a rivet can be detected at the moment of crimping the rivet, and complete automation is also easy.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of the entire device showing an embodiment of the device according to the present invention, Figs. 2 to 5 are explanatory diagrams of the operation of main parts with rivets, and Figs. 6 to 8 are illustrations without rivets. FIG. 9 is a block diagram showing an example of the electric control section. 1...Fixed stand, 2...Lower mold, 4...Upper mold, 5...
...Tack, 7...Punch pin, 9...Direct switch.

Claims (1)

[Claims] 1 A device for simultaneously tightening multiple studs such as a bearing retainer, which includes a fixed base, which is capable of being raised and lowered on the fixed base for more than the tightening stroke of the studs, and which is always elastically held at the rising end position by a spring. A lower mold having a retainer mounting surface at the upper end and vertical through holes corresponding to each rivet position, and a recess for crimping the rivets on the upper surface, which is inserted into each through hole of the lower mold so as to be able to be raised and lowered. , which can be raised and lowered individually through the rivets when the rivets are crimped, and are always elastically held at the upper end position by a spring with a lower elasticity than the spring of the lower mold, and
When the rivets are tightened, they descend in advance of the lower die and come into contact with the fixed base, and the upper surface at the rising end position is lower than the retainer mounting surface of the lower die at the rising end position. a plurality of positioned punch pins, an upper mold provided above the lower mold in correspondence with the punch pins so as to be movable up and down for more than the crimping stroke of the rivets, and installed between each of the punch pins and a fixed base, A rivet crimping device comprising: a detector that individually detects the relative displacement of each punch pin in the vertical direction with respect to the fixed base.