JPH0217296B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an electric screwdriver that automatically tightens screws and adjusts the position of parts of electronic equipment.

[Technical background of the invention]

In recent years, devices have been developed that automatically adjust the tightening and loosening of these pins and screws in response to playback signals while playing back the videotape, for example for adjusting guide pins and position setting screws in the videotape running system. is being developed. In this type of device, electric screwdrivers each having a bit are disposed corresponding to the position of a pin or screw to be adjusted, and adjustment is performed by rotating each of these electric screwdrivers. FIG. 6 shows an example of the configuration of the electric screwdriver. In the figure, reference numeral 10 denotes a cylindrical transmission shaft that is rotated by the driving force of a motor (not shown), and this transmission shaft 10 is rotatably fixed by a bearing 21 in a fixing hole provided in a base 20. Retained.
Note that 22 and 23 are nuts for maintaining the transmission shaft 10 in a fixed state. A moving shaft 30 is inserted into the hollow part of the transmission shaft 10 so as to be movable in the vertical direction A-A'. It is energized by A. The biasing force provided by the compression spring 32 is for pressing a bit 40, which will be described later, against a screw 60, which is a rotated component. Note that the moving range of the moving shaft 30 is the same as that of the transmission shaft 1.
Pin 3 of moving shaft 30 within long window 11 provided at 0
3 is defined as the range in which it can move.

On the other hand, a bit 40 is inserted into the tip of the hollow portion of the transmission shaft 10. A recess 41 is formed on the circumferential surface of the proximal end of this bit 40.
By engaging the steel ball 12 with the transmission shaft 10 using the adapter 50, the bit 40 is held so as not to fall off the transmission shaft 10. In addition, the above adapter 50
is constantly pushed downward by a compression spring 51 provided between the retaining ring 52 and the bit 40, thereby maintaining the inserted state of the bit 40. Further, a pin 42 is provided protruding from the circumferential surface of the intermediate portion of the bit 40, and by engaging this pin 42 with the groove 13 of the transmission shaft 10, the bit 40 rotates integrally with the transmission shaft 10. .

Therefore, when tightening or loosening the screw 60 using an electric screwdriver with such a configuration, first align the screw 60, and then move the base 2.
The electric screwdriver is lowered completely until the tip of the bit 40 is seated on the rotation stopper of the screw 60. In this state, a motor (not shown) is driven to rotate the bit 40, thereby tightening or loosening the screw 60. Therefore, by using a device equipped with such an electric screwdriver, everything from setting the bit to the screw 60 to tightening or loosening can be performed automatically, which saves work compared to when the operator manually adjusts the screw 60. Efficiency can be greatly increased.

[Problems with background technology]

However, although this type of conventional adjustment device does have the function of positioning the bit 40 with respect to the screw head, this function alone cannot always ensure that the bit 40 is seated securely on the screw head. In other words, if the direction of the screw head and the direction of the bit 40 are different, when the bit 40 is lowered, the bit 40 will only come into contact with the top of the screw head and will not stop the screw 60 from turning. will not be seated. In such a state, even if the bit 40 is rotated, the screw 60 will not rotate at all, and as a result, adjustment may not be possible, or if the bit 40 suddenly engages with the stopper of the screw 60 during rotation operation. This is extremely undesirable since the rotation stopper of the screw 60 or the bit 40 may be damaged.

Furthermore, in order to avoid the above-mentioned situation, it is necessary for the operator to visually confirm whether or not the bit is securely seated on the rotation stopper of the screw 60 before rotating the bit, which saves the operator's time and effort. was increasing, leading to a decrease in adjustment efficiency.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric screwdriver that can easily and reliably detect the seating state of a bit relative to a rotated component, thereby allowing reliable and efficient adjustment.

[Summary of the invention]

The present invention involves inserting a moving shaft movably in the axial direction into a hollow part of the transmission shaft, inserting a bit that is biased toward the tip by a spring, and detecting the position of the transmission shaft through a long window facing the transmission shaft. The seating detection means receives a signal from the bit and detects the seating state of the bit. This detection timing is determined by the detection timing specifying means when one of the pair of phase detectors detects a notch at a position corresponding to the bit tip shape of the detection disk provided on the transmission shaft. However, when it is detected that the bit is not seated, the bit is rotated until the notch in the detection disc is detected by the other phase detector, and the bit is seated again during or after this rotation. This is to operate the detection means.

[Embodiments of the invention]

FIG. 1 shows the configuration of an electric screwdriver according to an embodiment of the present invention. In this figure, the same parts as in FIG. 6 are given the same reference numerals and detailed explanations will be omitted.

A pair of columns 72 and 75 are erected on the base 20, and the transmission shaft 1 is connected to these columns 72 and 75.
A light emitting optical system 71 and a light receiving optical system 76 as position detectors are installed so as to face each other through the long window 11 . These light emitting optical systems 71
The light receiving optical system 76 projects the detection light guided from the light emitting unit 74 via the optical fiber 73 into the long window 11, and condenses the detection light that has passed through the long window 11 to produce a light beam. The signal is sent to a light receiving section 78 via a fiber 77, and the light receiving section 78 converts it into an electrical signal. Furthermore, the positions of the light emitting optical system 71 and the light receiving optical system 76 are set at bit 4.
0 is the rotation stopper 61 of the screw 60 as shown in FIG. 2a.
When the bit 40 is seated on the stopper 61 of the screw 60, it does not face the upper end of the moving shaft 30, and when the bit 40 is not seated on the stopper 61 of the screw 60 as shown in FIG. It is set to be shaded. In other words, in order to be able to determine the step H that occurs depending on whether or not the bit 40 is seated,
The positions of the light emitting optical system 71 and the light receiving optical system 76 are set.

On the other hand, a detection disk 80 is fitted on the circumference of the transmission shaft 10, and phase detectors 81, 82 are mounted on the circumference of the detection disk 80 with the detection disk 80 sandwiched therebetween.
is located. These phase detectors 81,8
2 are arranged at a distance of θ from each other as shown in FIG.
Generates TS1 and TS2. In addition, the detection disc 80
The position of the notch 84 is as shown in FIG.
It is initially set to match the orientation of 0.
Also, the separation angle θ of each of the phase detectors 81 and 82 is
is set to 90° or a slightly larger value.

By the way, the electric screwdriver of this embodiment has a control section 9.
It is equipped with 0. This control section 90 has, for example, a microcomputer as a main control section, and its functions include seating detection means 90a, detection timing specifying means 90b, as shown in FIG.
Seating setting control means 90c. The seating detection means 90a drives the light emitting section 74 to generate detection light, and determines whether or not the detection light passes between the light emitting optical system 71 and the light receiving optical system 76, that is, the bit 40.
The seated state of the seat is detected from the light reception signal of the light receiving section 78. The detection timing specifying means 90b causes the seating detecting means 90a to detect the seating at the time when the pulse signal TS1 is generated from the phase detector 81 as the seating detection timing. The reason for providing this detection timing specifying means 90b is that since the seating detection means 90a performs detection through the long window 11 of the transmission shaft 10, the light emitting optical system 71 and the light receiving optical system 76 face this long window 11. This is because the seated state can only be detected when the seat is in the seated position. The seating setting control means 90c, when the seating detection means 90a detects that the person is not seated,
The motor drive circuit 91 is driven to rotate the transmission shaft 10 through 90 degrees, thereby seating the bit 40 on the stopper 61 of the screw 60. At this time, the amount of rotation (90 degrees) of the transmission shaft 10 is determined by the phase detector 8.
It is set by monitoring the pulse signal TS2 generated from TS2.

Next, the operation of the electric screwdriver configured as above will be explained. When the bit 40 is lowered to the head of the screw 60 and a notification to that effect is sent from the adjustment control section (not shown), the control section 90 first drives the light emitting section 74 to generate detection light, and in this state, the phase detector 8
1, and if the pulse signal TS1 is generated, it is determined that the light emitting optical system 71 and the light receiving optical system 76 are facing the long window 11 of the transmission shaft 10, and the light receiving section 78 A determination is made as to whether or not the person is seated by capturing the light reception signal of the person. For example, if the bit 40 is seated on the rotation stopper 61 of the screw 60, the moving shaft 30 will be in a lowered state as shown by the solid line in FIG. Since the light is then guided to the light receiving section 78, the control section 90 can determine from the light reception signal that the seat is seated. On the other hand, if the bit 40 is not seated as shown in FIG. 2b, for example,
Since the moving axis 30 is located above as shown by the broken line in FIG. 1, the detection light is blocked by the moving axis 30 and not guided to the light receiving optical system 76, and as a result, no light receiving output is obtained from the light receiving section 78. For this reason, the control unit 90
It can be determined that the person is not seated.

On the other hand, the pulse signal TS from the phase detector 81
1 is not generated, and as a result, the light emitting optical system 71
And if it is determined that the light receiving optical system 76 is not facing the long window 11 of the transmission shaft 10, the control unit 9
0 drives the motor drive circuit 91 to rotate the transmission shaft 10 as shown in FIG. 3 C1. During this rotation, a pulse signal TS1 from the phase detector 81 is output.
The emission optical system 71 and the light reception optical system 76 are monitored when the pulse signal TS1 is generated.
It is determined that the seat is now facing the long window 11 of the transmission shaft 10, and the seated state is determined based on the light reception signal from the light receiving section 78.

Now, if it is determined that the seat is not seated in these seat state determinations, the control section 90 first drives the motor drive circuit 91 in this state to rotate the transmission shaft 10 in the direction of arrow C1 in FIG. let Then, the rotation is stopped when the pulse signal TS2 is generated from the phase detector 82, that is, when the rotation is a little more than 90 degrees, and then the detection disk 80 is turned in the opposite direction (arrow C2). The notch 84 is the phase detector 8
Return to the position detected in step 1. That is, this causes the bit 40 to rotate against the rotation stopper 61 of the screw 60.
Perform the seating setting operation. After the rotation operation is completed, the light reception signal from the light receiving section 78 is taken in and the seating state is determined based on the level. If the seating is confirmed by this determination, a start signal is sent to the adjustment control section (not shown). output and start adjustment operation. On the other hand, if seating is not confirmed in the seating determination after the rotation described above, the transmission shaft 10 is reciprocated in the directions of the arrows C1 and C2, and the seating determination is performed after this rotation is completed. Thereafter, the above rotation operation is repeated until seating is confirmed, and when seating is confirmed, the adjustment control section is caused to start adjusting the screw height as described above.

As described above, in this embodiment, by providing the electric screwdriver with a means for determining the seating state, it is possible for the operator to visually check the seating state, which cannot be reliably achieved simply by aligning the bit 40 with respect to the screw 60. The determination can be made easily and reliably without relying on observation or the like. Therefore, it is possible to eliminate the problem of shifting to the adjustment operation even though the person is not securely seated, and it is also possible to significantly reduce the burden on the operator. Furthermore, in this embodiment, if seating is not confirmed, the motor is driven to rotate the transmission shaft 10, thereby setting the bit 40 to the head of the screw 60, so that the seating setting operation is performed. This can be done automatically without depending on the operator's operation, which not only reduces the worker's effort but also allows the seating setting to be performed reliably and quickly, greatly increasing adjustment efficiency.

Note that the present invention is not limited to the above embodiments. For example, in the above embodiment, an example was explained in which the height of the screw 60 was adjusted, but the present invention may also be applied to adjust the position of a component. In other words, as shown in FIGS. 5a to 5c, a notch 101 for adjustment is provided in a substrate 100 to be adjusted, and a pair of pins 102 are provided upright on a base 110 at a position facing the notch 101. On the other hand, the fifth
It can also be applied to the case where the position of the board 100 is adjusted by seating the tip of the bit 40 in the notch 101 and rotating the bit 40 using each pin 102 as a fulcrum as shown in FIG. good. In this case, depending on the orientation of the bit 40, the bit 40 may be attached to the substrate 100 as shown in FIG.
This means that it will not come into contact with the upper surface of and sit in the notch 101. Therefore, even in such a case, if the seating detection and seating setting described in the above embodiment are performed,
As in the previous embodiment, the seat can be easily and reliably seated without relying on the operator's operation. By the way, in this case, as shown in FIGS. 5b and 5c, when the bit 40 is lowered, the bit 40 touches the substrate 10.
It may get stuck between the 0 side part and each pin 102. In this situation, the notch 1
The seating detection means 9 even though the person is not sitting on the seat 01.
At 0a, it is determined that the person is seated, which causes problems in adjustment, which is not preferable. In order to prevent this, paying attention to the fact that the directions of the sides of the substrate 10 and the gaps between the pins 102 are known in advance, the directions of the notches 84 of the detection disk 80 and the bits 40 are shown in FIG. Before lowering the bit 40, set the detection disk 80 and the phase detector so that the direction of the bit 40 does not match the direction of the side surface of the substrate 10 and the gap between each pin 102. Set the initial position of bit 40 based on the detection result of 81,
After that, the bit 40 may be lowered.

Further, in the above embodiment, the case where a negative type bit is used has been described, but a positive type bit may also be applied. However, in this case, the rotation angle θ of the transmission shaft 10 when setting the seat may be 45°.
Further, the control section 90 controls the transmission shaft 10 according to the type of the bit in case the bit is to be replaced and used.
It may also be provided with an input means for setting various parameters such as the rotation angle. In addition, the structure of the driver body, the configuration of the seating detection means, the types of rotated parts, etc. can be modified in various ways without departing from the gist of the present invention.

〔Effect of the invention〕

As described in detail above, according to the present invention, the seating state of the bit is detected by the seating detection means upon receiving a signal from the position detectors arranged opposite to each other via the long window of the transmission shaft, and the bit is seated. If not, the bit is rotated until the notch in the detection disc is detected by a pair of phase detectors, and the seated state is detected again during or after this rotation, so the rotated part The seating status of the bit can be easily and reliably determined, and even if the bit is not seated, the bit can be automatically seated against the rotated part, reducing the burden on the worker and greatly increasing adjustment efficiency. We can provide an electric screwdriver that can be made more expensive.

[Brief explanation of drawings]

1 to 4 are for explaining an electric screwdriver according to an embodiment of the present invention, FIG. 1 is a configuration diagram of its main parts, and FIGS. 2a and 2b are side views showing the seated state of the bit, respectively. A sectional view, FIG. 3 is a plan view showing the configuration of the detection disk and the arrangement position of the phase detector,
FIG. 4 is a block diagram showing the functional configuration of the control section, and FIGS. 5 a to 5 c are for explaining other embodiments of the present invention, and a and b explain the seating state of the bit with respect to the adjustment target. FIG. 6 is a side sectional view showing the configuration of the main body portion of the driver for explaining a conventional electric screwdriver. 10...Transmission shaft, 11...Long window, 12...Steel ball, 13
... Groove, 20... Base, 21... Bearing, 22, 23... Nut, 30... Moving shaft, 32, 51... Compression spring, 4
0... Bit, 41... Recess, 42... Pin, 50... Adapter, 52... Retaining ring, 60... Screw, 61... Rotation stopper, 71... Light emitting optical system, 72, 75... Support, 7
3, 77... Optical fiber, 74... Light emitting section, 76... Light receiving optical system, 78... Light receiving section, 80... Detection disk, 8
DESCRIPTION OF SYMBOLS 1, 82... Phase detector, 84... Notch, 90... Control part, 90a... Seating detection means, 90b... Detection timing designation means, 90c... Seating setting control means, 9
DESCRIPTION OF SYMBOLS 1... Motor drive circuit, 100... Board, 101... Notch, 102... Pin.

Claims (1)

[Claims] 1. A transmission shaft having a hollow portion formed at least at the tip and a long window formed at the other end, which is rotated by the driving force of a rotational drive source, and a transmission shaft that is inserted into the hollow portion of the transmission shaft so as to be movable in the axial direction. a moving axis,
a bit that is inserted into the hollow portion of the transmission shaft so as to be movable in the axial direction in contact with the moving shaft and rotates integrally with the transmission shaft; and a spring that constantly biases the bit in the direction of the distal end of the transmission shaft. , a position detector disposed opposite to the transmission shaft through a long window and detecting the axial position of the moving shaft; and a position detector provided on the transmission shaft and adapted to the shape of the tip of the bit inserted into the transmission shaft. a detection disc having a notch formed at a position; a pair of phase detectors arranged according to the shape of the tip of the bit to detect the notch in the detection disc; seating detection means for detecting the seating state of the bit; detection timing designation means for causing the seating detection means to perform a detection operation when receiving a signal from one of the phase detectors; and the seating detection means. When it is detected that the bit is not seated, the rotary drive source is driven to rotate the bit until the other phase detector detects the notch in the detection disk, and this rotation operation is performed. An electric screwdriver characterized by comprising: seating setting control means for operating the seating detection means again during the rotation or after the rotation is completed.