JPH0463328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a torque detection device for detecting torque of a motor or the like, and particularly to a torque detection device with excellent torque responsiveness.

[Prior Art] Conventionally, as a torque detection device for detecting the torque of a motor or the like, the one shown in FIG. 7 is known.

In FIG. 7, for example, the motor whose torque is to be measured is connected to a shaft 61 to which a drum 60 is attached, and when a load is applied to the drum 60 by a load mechanism 62, the torque of the motor is measured. .

To explain the load mechanism 62, the gear motor 6
3 is connected to a threaded rod 64, and this threaded rod 6
4 causes the bracket 66 to which the nut 65 is attached to stroke back and forth. The pin 6 embedded in the notch of this bracket 66
7 and 68 are inserted into elongated holes 73 and 74 of arms 71 and 72 which are supported by support shafts 69 and 70,
The stroke movement of the bracket 66 causes the arm 71,
It can be changed to 72 lever movements. Also arm 7
1 and 72 have crimp pins 75 and 76,
By the lever movement of the arms 71 and 72, the brake lining 7, which is supported by the support shafts 77 and 78, is
9 and 80 are pressed against the drum 60 side with a strong force. This pressing force on the drum 60 applies a load to the motor whose torque is measured.

The other end of a coil spring (not shown) whose one end is fixed to the housing is attached to the bracket 66, and when a pressing force is applied to the drum 66, the entire load mechanism 62 rotates by reaction until it is in equilibrium with the coil spring. do. Torque is measured by detecting this rotation with an angle sensor such as a magnetic potentiometer and converting it into a voltage proportional to torque through an electric circuit.

[Problems to be Solved by the Invention] By the way, in the above-described torque detection device, the entire load mechanism 62 is controlled by a coil spring, and the inertia seen from the motor whose torque is detected is large, resulting in a poor torque response. There is a problem that it is bad.
Particularly when trying to detect the torque of a stepping motor, if the inertia is large, the motor cannot follow the drive pulse signal and the motor loses synchronization, causing a problem that the torque cannot be detected accurately.

Further, the load mechanism 62 has a problem in that the transmission path of the force that applies the pressing force to the drum 60 is long, and the load cannot be smoothly applied to the motor.

Further, in the load mechanism 62, there is a force loss in the transmission path, so when changing the load, a delay occurs in the transmission time, resulting in a problem of poor load response.

Therefore, the present invention was proposed to solve these conventional problems, and it can reduce the inertia seen from the motor where torque is detected, improve torque response, and provide a smooth motor. The object of the present invention is to provide a torque detection device that can apply a load to the torque detection device.

[Means for Solving the Problem] In order to achieve this object, the torque detection device of the present invention includes a drum that rotates by connecting a connecting shaft to the rotating shaft of a detection rotary machine, and a drum that is horizontal to the drum surface of the drum. It consists of a leaf spring with a brake lining attached to one end that is crimped to the drum, a fixed rail, and a movable rail that slides perpendicularly to the drum surface on the fixed rail.The other end of the leaf spring is attached to this movable rail. a linear guide table that supports the leaf spring horizontally with respect to the drum surface; a threaded rod that is screwed into a female threaded portion formed perpendicularly to the drum surface within the moving rail and has a spur gear attached thereto; , a gear motor equipped with a spur gear or a meshing gear, and a sensor mounting plate supported at the other end of the leaf spring are attached perpendicularly to the surface of the leaf spring to determine the amount of deflection of one end of the leaf spring. and a displacement sensor that detects without contact, drives the gear motor to press the brake lining to the drum, detects the amount of deflection of the leaf spring with the displacement sensor, and detects the torque of the rotating machine to be detected. It is characterized by

[Operation] Therefore, in the present invention, the brake lining attached to the leaf spring is crimped to the drum and the amount of deflection of the leaf spring is detected to detect the torque of the rotating machine to be detected such as a motor. The load seen from the rotating machine is reduced and torque response is improved.

Also, since the load is applied using a gear motor and screw jack, the load can be applied smoothly to the drum.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, the basic idea of the present invention will be explained with reference to FIGS. 5 and 6.

In the figure, a rotating shaft of a rotating machine to be detected, such as a motor whose torque is to be measured, is connected to a connecting shaft 103 on which a drum 105 is attached on a concentric shaft.
Further, this drum 105 is provided with leaf springs 132, 13.
Brake linings 106 and 107 attached to brake holders 140 and 145 apply strong pressure from above and below. The application of this pressure force is applied to the support points O ₁ of the plate springs 132 and 133,
This is done by a screw shaft and gear motor installed on the _O2 side. Leaf springs 132, 133 on top and bottom
are provided in order to balance the pressure by applying pressing force evenly to the top and bottom of the drum 105, and to be able to measure the torque in both rotational directions.

Here, the diameter of the drum 105 is D, the pressing force (total legal pressure) by the brake linings 106 and 107 is P, the force acting in the tangential direction of the drum 105 due to the pressing force P is F, and the drum 105 and the brake lining 106 are , 107 is μ, and the torque acting on the drum 105 is T, the torque T is as follows: T=F・D=μP・D. From this equation, it can be seen that by increasing the pressing force P or increasing the friction coefficient μ, the drum 10
5 can be made smaller. Torque T
In this detection, it is necessary to reduce the inertia seen from the motor side, so it is necessary to reduce the diameter D and make the drum 105 as small as possible.

Further, since the leaf springs 132 and 133 are bent in proportion to the force F acting in the tangential direction, the leaf springs 13
2,133 spring constant is K, leaf spring 132,13
If the amount of deflection of No. 3 is δ, then the amount of deflection δ is as follows: δ=K·F. From this equation, F=δ/K, and by substituting this into the previous equation, the torque T becomes T=δ/K·D.

Therefore, the amount of deflection δ of the leaf springs 132, 133
By detecting , the torque T of the motor can be measured.

This deflection amount δ is detected without contact by displacement sensors 138 and 139, such as magnetic displacement sensors, which are disposed on the sides of the tips of the leaf springs 132 and 133. In the illustrated example, since the drum 105 is rotating to the right, the displacement sensor 139 detects the amount of deflection δ of the leaf spring 133, which is deflected far away from the sensor.

The displacement sensors 138 and 139 are connected to the leaf spring 13
It is attached to a sensor mounting plate which is fixed via a spacer at the support points O ₁ and O ₂ of No. 2,133.

Note that when the brake linings 106 and 107 come into pressure contact with the drum 105, the leaf springs 132 and 133
is the rotational displacement around the support points O ₁ and O ₂ , but
If the length of the leaf springs 132, 133 is made sufficiently large compared to the amount of deflection δ, it can be regarded as a linear displacement.

In this way, the torque detection device of the present invention does not rotate the entire load mechanism 62 as in the conventional case, but only the leaf springs 132, 133 to which the brake linings 106, 107 are attached are displaced, and the torque is detected. The inertia seen from the motor is small,
Good torque response.

Next, an embodiment of the torque detecting device will be described with reference to a side view in FIG. 1, a plan view in FIG. 2, and a front view showing main parts in FIG. 3.

In the figure, a connecting shaft 3 is rotatably supported by bearings 2, 2 provided on the front plate 1a of the housing 1, and a motor or the like whose torque is measured is attached to the tip of the connecting shaft 3. An attachment 4 is attached to which the rotating shaft of the rotating machine to be detected is connected. Further, a drum 5 having a plurality of fin structures is concentrically attached to the connecting shaft 3, and the drum 5 is housed in the housing 1. By forming the drum 5 into a fin structure as described above, the heat generated when the drum 5 is strongly pressed by the brake linings 6 and 7, which will be described later, can be effectively dissipated. The rear end of the connecting shaft 3 is supported by a bearing 9 provided on a support plate 8. Further, behind the support plate 8, a rotary encoder 10 is arranged to measure the rotational speed of a motor connected to the connecting shaft 3. The rotational speed is detected by detecting a hole in a disc 11 attached to the end of the connecting shaft 3 using a photo sensor or the like.

Further, in the rear part of the housing 1, a gear motor 13 is fixed upside down to a support plate 12, and a pinion gear 14 is attached to the drive shaft of the gear motor 13. On the left side of the gear motor 13 in the figure, linear guide tables 15 and 16 are provided one above the other. This linear guide table 15,
16 consists of fixed rails 17, 18 and moving rails 19, 20, respectively. The protrusion 19A of the upper moving rail 19 has a left-hand thread, for example, and the protrusion 20A of the lower moving rail 20 has a reverse thread, for example a right-hand thread. Further, the threaded rods 22 that are threaded into the respective reverse threads in the protrusions 19A and 20A are connected to the bearing 23 of the support plate 12 and the support plate 21 below the bearing 23.
It is rotatably supported by a bearing 24. Reverse male threads are formed on the top and bottom of this threaded rod 22. Between the protrusion 19A and the support plate 12,
Coil spring 25 that urges the moving rail 19 upward
is provided on the outer periphery of the threaded rod 22, and the protrusion 2
A coil spring 26 is provided on the outer periphery of the threaded rod 22 between 0A and the support plate 21 to bias the moving rail 20 downward. On the threaded rod 22, a spur gear 27 that meshes with the pinion gear 14 is attached to the support plate 12,
It is installed between 21. As a result, the gear motor 13 rotates, and the fixed rails 17, 1
8, the moving rails 19, 20 slide toward each other or away from each other.
The upper and lower limits of sliding of these moving rails 19 and 20 are:
It is detected by photo interrupters 28 and 29.

Furthermore, the stepped portions 19B of the moving rails 19, 20,
20B has a plate spring 32,
33 is fixed. Also, the moving rails 19, 2
There are screws 3 on the surfaces of the protrusions 19A and 20A of 0.
4 and 35, sensor mounting plates 36 and 37 are fixed to the right side of the leaf springs 32 and 33. Displacement sensors 38 and 39 for detecting the amount of deflection of the tips of the leaf springs 32 and 33 are mounted on the sensor mounting plates 36 and 37 perpendicularly to the surfaces of the leaf springs 32 and 33.

Further, a brake holder 40 to which a brake lining 6 is attached is slidably provided at the tip end of the upper plate spring 32 on the side of the drum 5 by means of a pin 42 via a bush 41 . This brake holder 40 is provided with slide adjustment screws 43 and 44 on the left and right sides for aligning the center of the brake running 6 and the center of the drum 5.

Similarly, a brake holder 45 to which a brake lining 7 is attached is also slidably provided at the end of the lower plate spring 33 on the side of the drum 5 by means of a pin 47 via a bush 46 . Slide adjustment screws 48, 4 are provided on the left and right sides of this brake holder 45.
9 is provided.

The brake linings 6 and 7 disposed above and below the drum 5 are made of urethane rubber, asbestos, hard carbon, etc., which have a high coefficient of friction and are less deformed in the compression direction.

In the torque detection device configured in this way, when the gear motor 13 is driven so that the plate springs 32 and 33 approach each other, the fixed rails 17 and 18
The moving rails 19 and 20 slide while being guided on the top.
The brake linings 6 and 7 press against the drum surface 5a of the drum 5 with strong pressure. At this time, the plate springs 32 and 33 are deflected in proportion to the torque of the motor connected to the connecting shaft 3. By detecting this deflection amount with the displacement sensors 38 and 39, the starting torque or rotational torque of the motor can be determined. It can be measured.

For example, the thickness of leaf springs 32 and 33 is 2 mm, and the width is
When the distance from the support point of leaf springs 32 and 33 to the center of drum 5 is 70 mm, the torque is
In the case of 800 g cm, the amount of deflection is, for example, 0.3 mm.
This amount of deflection, for example, 0 to 1 mm is, for example, 1 μm.
The displacement sensors 38 and 39 have a resolution of .

Here, since the linear guide tables 15 and 16 are used in the torque detection device,
The support points of the leaf springs 32 and 33 do not wobble, and even pressure is applied to the top and bottom of the drum 5.

In addition, the force is doubled by the gear motor 13 and the screw jack to apply the crimping force to the drum 5, but the gap between the brake linings 6, 7 and the drum 5 can be set narrowly, and the amount of displacement in the direction of the drum 5 after crimping is Since it is extremely small, the gear motor 13,
Furthermore, the gear ratio between the spur gear 27 and the pinion gear 14 and the thread pitch of the threaded rod 22 can be set to further increase the pressing force.

Additionally, the plate springs 32 and 33 are attached to the sensor mounting plates 36 and 3.
Since it moves up and down parallel to 7, only the rotational torque component can be detected without noise components.

In addition, the conventional torque measurement time (scan time) was approximately one minute, but in the above torque detection device, the rotation of the gear motor 13 is directly transmitted to the threaded rod 22, and also to the brake linings 6 and 7 that press the drum 5. , the torque measurement time is shortened to about 5 seconds.

Next, a circuit for converting the sensor output from the displacement sensors 38 and 39 into a voltage proportional to torque will be explained based on FIG. 4.

In FIG. 4, the output from the displacement sensor 38 or 39 is amplified by a dedicated amplifier 50, and converted into a voltage proportional to torque by an operational amplifier 51 in the subsequent stage.
Then, a torque detection signal is output from the output terminal 52. The variable resistor 53 is for zero point adjustment.

Note that the present invention can be applied to torque detection of a rotating machine to be detected, such as an internal combustion engine, in addition to a motor.

[Effects of the Invention] As explained above, in the present invention, a plate spring with a brake lining attached is pressed onto a drum using a gear motor and screws, and the amount of deflection of the plate spring is detected without contact using a displacement sensor to measure torque. ing.

Therefore, the load seen from the motor whose torque is detected becomes smaller, and the torque responsiveness becomes better. In particular, when the torque detection device of the present invention is used to detect the torque of a stepping motor, the torque can be detected satisfactorily without causing step-out.

In addition, since the pressing force is applied to the drum by a gear motor and a screw jack, the load can be applied smoothly and the time required to measure torque can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of a torque detection device according to an embodiment of the present invention, FIG. 2 is a sectional view of the torque detection device seen from above, and FIG. 3 is a front view showing the main parts of the torque detection device. , FIG. 4 is a detection circuit diagram used for detecting the amount of deflection of the leaf spring in the torque detection device,
FIG. 5 is a front view for explaining the concept of the present invention, FIG. 6 is a perspective view of FIG. 5, and FIG. 7 is a perspective view showing essential parts of a conventional torque detection device. 3,103...Connection shaft, 4...Attachment, 5,105...Drum, 6,7,106,1
07... Brake lining, 13... Gear motor, 14... Pinion gear, 15, 16... Linear guide table, 17, 18... Fixed rail,
19, 20...Moving rail, 22...Threaded rod, 2
7... Spur gear, 32, 33, 132, 133...
Leaf spring, 36, 37...Sensor mounting plate, 38, 3
9,138,139...displacement sensor, 40,4
5,140,145...brake holder, 42,
47... Pin, 43, 44, 48, 49... Slide adjustment screw, 50... Dedicated amplifier, 51... Operational amplifier, 52... Output terminal.

Claims (1)

[Claims] 1. A drum that rotates by connecting a connecting shaft to the rotating shaft of the rotating machine to be detected, a plate spring with a brake lining attached to one end that is pressed horizontally to the drum surface of the drum, a fixed rail, and a It consists of a moving rail that slides perpendicularly to the drum surface, the other end of the leaf spring is attached to the moving rail, and a linear guide table supports the leaf spring horizontally to the drum surface, A threaded rod having a flat gear screwed into a female thread formed perpendicular to the drum surface, a gear motor having a gear meshing with the flat gear, and a screw rod supported by the other end of the leaf spring. and a displacement sensor that is mounted perpendicularly to the plate spring surface on the sensor mounting plate and detects the amount of deflection of one end of the plate spring without contact, and drives the gear motor to move the brake lining to the drum. A torque detection device characterized in that the torque of the rotating machine to be detected is detected by detecting the amount of deflection of the plate spring with the displacement sensor.