JPH0874980A - Belt-type continuously variable transmission - Google Patents

Abstract

PURPOSE: To provide a belt-type continuously variable transmission wherein a detecting means for transmitting speed can be easily arranged, and the detection with high precision can be performed, and which can cope with slipping or cutting of the transmitting belt. CONSTITUTION: In a belt-type continuously variable transmission constituted by winding a transmitting belt 11 formed by connecting many transmitting pieces A arranged in the peripheral direction of an endless elastic belt at the specific distance to the endless elastic belt by a metallic connecting tool 16 around a motor side pulley 9 and a load side pulley 10, a pickup sensor 23 for electromagnetically detecting the passage of the connecting tool in the transmitting belt 11 is arranged near a winding circuit of the transmitting belt 11 so as to face it. Moreover, a belt rotational speed detecting means 25 for calculating the rotational speed of the transmitting belt 11 on the basis of the detected output from the pickup sensor 23 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive side pulley in which a plurality of transmission pieces arranged in a circumferential direction of an endless elastic belt are connected to the endless elastic belt by metal connecting members. The present invention relates to a belt type continuously variable transmission configured by being wound around a load side pulley.

[0002]

2. Description of the Related Art It is known to use a magnetic pickup sensor as an example of detecting means for detecting the transmission speed when controlling the speed change of a belt type continuously variable transmission. . The rotation detecting means using this electromagnetic pickup sensor is provided with a magnetic metal protrusion or a gear-like member provided on a rotating body to be detected, and the pickup sensor is fixedly arranged in close proximity to a tip of the protrusion or a gear tooth tip. Then, the rotation speed of the rotating body is calculated by counting the number of output pulses generated from the pickup sensor with the passage of the protrusion in set time units.

[0003]

However, in the form in which one or a plurality of magnetic metal projections are provided on the rotating body, it is difficult to perform highly accurate detection because the detection pitch of the projections is rough, and the gear-like member is used. In the configuration provided, more gear teeth can be provided compared to the above-mentioned protrusions, so detection can be performed with relatively high accuracy, but it is necessary to separately process and attach the gear-like member, resulting in high cost. Tended to. Furthermore, in the past, the transmission belt was used to detect the transmission speed by using the transmission hand, so if the transmission belt slips due to a high load or the transmission belt is broken, the transmission belt will be transmitted. There was no way to quickly know that the belt was slipping or that the transmission belt was broken. Therefore, it has been difficult to quickly adjust the output of the driving part or stop the driving part. The present invention has been made in view of the above-mentioned circumstances, and is capable of easily installing a transmission speed detecting means, while performing accurate detection, and quickly for slipping or cutting of a transmission belt. It is an object of the present invention to provide a belt type continuously variable transmission that can be used.

[0004]

In order to achieve the above object, a belt type continuously variable transmission according to the first aspect of the present invention comprises a plurality of metal transmission pieces arranged at predetermined intervals in the circumferential direction of an endless elastic belt. In a belt-type continuously variable transmission constituted by winding a transmission belt connected to the endless elastic belt with a connecting member around a driving side pulley and a load side pulley, the passage of the connecting member in the transmission belt is electromagnetically coupled. A belt rotation speed detecting means for detecting the rotation speed of the transmission belt based on a detection output from the pickup sensor. The feature is that it is provided. In order to achieve the above-mentioned object, the belt type continuously variable transmission according to the second aspect of the present invention includes a plurality of transmission pieces arranged at predetermined intervals in the circumferential direction of the endless elastic belt, which are connected to the endless elastic belt by a metallic connector. In a belt type continuously variable transmission constituted by winding a connected transmission belt around a drive side pulley and a load side pulley, a pickup sensor for electromagnetically detecting passage of the connecting tool in the transmission belt, A belt rotation speed detecting means for calculating the rotation speed of the transmission belt based on the detection output from the pickup sensor is provided and is opposed to the winding path of the transmission belt, and the rotation of the drive side pulley is provided. A driving-side rotation speed detecting means for detecting a moving speed is provided, and the rotation speed detected by the driving-side rotation speed detecting means is used as a reference rotation speed, and the reference rotation speed and the belt rotation speed are set. Wherein configuration that you have provided a speed difference detecting means for calculating a difference between the rotational speed of the detected transmission belt at a speed detecting means. The operation and effect of this characteristic configuration are as follows.

[0005]

That is, according to the first aspect of the present invention, a coupling tool for coupling the transmission piece of the transmission belt to the endless elastic body is used, the coupling tool is detected by the pickup sensor, and the belt is rotated based on the detection. The rotation speed of the transmission belt is detected by calculating the rotation speed of the transmission belt by the speed detection means. Therefore, a large number of connecting tools can be provided at a pitch smaller than that of the conventional detection projections, and the number of pulses generated per unit time can be increased to improve the detection accuracy. Further, it is not necessary to use a dedicated gear-shaped body as a detection target for the pickup sensor.

According to the second aspect of the invention, the rotation speed of the driving pulley is separately detected as the reference rotation speed, and the speed difference is calculated by comparing with the detected rotation speed of the transmission belt. It is possible to easily detect whether or not the belt is slipping.

[0007]

As described above, according to the first aspect of the present invention, since the connecting tool, which is an essential part of the transmission belt, is used as the detection target piece for the pickup sensor, a large number of detection target pieces can be arranged at a small pitch. Although it is possible to perform highly accurate detection, it is not necessary to use a member such as a gear-shaped body exclusively for detection, which is effective in cost reduction.

Further, according to the second aspect of the present invention, it is possible to easily detect whether or not the transmission belt is slipping. Therefore, by changing and adjusting the output of the driving portion according to the degree of the slip, Slip can be eliminated and good power transmission can be performed.

Further, in common with the first and second inventions, when the transmission belt is cut off or comes off from the driving side pulley and the load side pulley, the pickup sensor no longer detects it. There is an advantage that an abnormality can be detected, an alarm can be issued, or the driving unit can be stopped quickly.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a riding type rice transplanter equipped with a belt type continuously variable transmission 1 of the present invention. In this riding type rice transplanter, an engine 5, a belt-type continuously variable transmission 1, and a mission case 6 as a driving part are mounted on a vehicle body 4 supported by a pair of left and right front wheels 2 and 2 and rear wheels 3 and 3 so that they can travel. In addition to being equipped, a seedling planting device 8 is attached to the rear end of the vehicle body 4 via a link mechanism 7 so as to be able to move up and down. The front wheels 2 and 2, the rear wheels 3 and 3 and the seedling planting device 8 are driven by the output power from the mission case 6.

As shown in FIG. 2, the belt type continuously variable transmission 1 extends over a driving pulley 9 mounted on an output shaft 5a of an engine 5 and a load pulley 10 mounted on an input shaft 6a of a transmission case 6. It is configured by winding the transmission belt 11. As shown in FIGS. 2 and 3, the transmission belt 11 includes a thin strip-shaped endless elastic belt 12 formed with locking projections 13 along the lateral direction of the belt at a constant circumferential pitch. It has a structure in which a transmission piece A is attached to each. The transmission piece A is configured by connecting and fixing a rectangular parallelepiped inner transmission piece 14 and an outer transmission piece 15 with a metal screw 16 as a connecting tool.

The driving pulley 9 has a pair of left and right pulley portions integrally formed, and the load pulley 10 has a pair of left and right pulley portions, one of which is a fixed split pulley 10a and the other of which is in the axial direction of the input shaft 6a. A movable split pulley 10b that is slidable along the movable split pulley 10b is provided, and a spring 17 that elastically biases the movable split pulley 10b so as to approach the fixed split pulley 10a is provided. Then, the fixed split pulley 10 is changed by changing the winding tension of the transmission belt 11.
By changing the distance between a and the movable split pulley 10b, and by changing the winding diameter with respect to the load side pulley 10, the rotation speed of the input shaft 6a is continuously changed.
A tension arm 18 for changing and adjusting the winding tension of the transmission belt 11 is provided so as to be swingably driven by an electric cylinder 19. The electric cylinder 19 is expanded / contracted by a control signal from the control device 20.

As shown in FIG. 2, a projection piece 21 made of magnetic metal is continuously provided at a position adjacent to the driving side pulley 9 of the output shaft 5a so as to rotate integrally with the output shaft 5a. A first pickup sensor 22 that electromagnetically detects the passage of the piece 21 is disposed in close proximity to and opposite to the first pickup sensor 22. Then, in the winding path of the transmission belt 11 wound around the driving side pulley 9 with respect to the driving side pulley 9, each transmission piece A is
16 made of magnetic metal for connecting the endless elastic belt 12
A second pickup sensor 23 as a pickup sensor for detecting the passage of the head is disposed so as to face the movement locus of the screw head and face it. Detection signals of these sensors 22 and 23 are input to the control device 20.

Then, the detection signal from the first pickup sensor 22 is input to the control device 20, and the rotation speed detection on the driving side for calculating the rotation speed of the output shaft 5a and thus the driving portion pulley 9 per unit time. Means 24 and belt rotation speed detection means 25, which receives the detection signal from the second pickup sensor 23 and calculates the rotation speed of the transmission belt 11 per unit time, are provided. Further, the speed difference detecting means for inputting and comparing the calculation result of the driving side rotation speed detecting means 24 and the calculation result of the belt rotation speed detecting means 25 to calculate the difference between the rotation speeds thereof. 26 is provided. When the difference between the rotational speeds obtained by the speed difference detecting means 26 is equal to or greater than a predetermined value, it is determined that the load is large, and the belt type continuously variable transmission 1 is operated so that the deceleration operation is performed. A shift control means 27 for outputting a signal for driving the cylinder 19 is provided. Further, the detection signal from the first pickup sensor 22 and the detection signal from the second pickup sensor 23 are input to the AND circuit 28, and the output signal from the AND circuit 28 is an H signal or an L signal among the binary signals. Belt abnormality determining means 29 for determining whether the signal is a signal
Is provided. That is, this belt abnormality determination means is
When power is being transmitted by the belt-type continuously variable transmission 1,
Normally, within the time T during which the first pickup sensor 22 detects the protruding piece 21, the second pickup sensor 23 sets screws 1
6 can be detected, and since the H signal is output from the AND circuit 28 within the time T, the output shaft 5a
If the H signal is not input from the AND circuit 28 continuously for a predetermined time longer than the rotation cycle of, the transmission belt 11 is in a disconnected state or is in an abnormal state in which it is disengaged from the driving pulley 9. It is judged that it has become. When the belt abnormality determination means 29 determines that the abnormality is present, an alarm is displayed on the control panel 31 with a lamp 30 or an audio notification is provided to inform the operator of the determination result.

[Other Embodiment] In the above embodiment, the second pickup sensor 23 which can detect the rotation speed of the output shaft 5a of the engine 5 is also provided, but only the first pickup sensor 22 is provided and the transmission speed is increased. May be detected. In the above-described embodiment, the driving pulley is not a split pulley structure, but the driving pulley may have a split pulley structure as in the load pulley of the above embodiment. In this case, the pickup sensor appropriately moves in the radial direction of the driving pulley in accordance with the shift operation so that the distance between the pickup sensor and the transmission belt is always maintained properly.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of drawings]

FIG. 1 is an overall side view showing a riding type rice transplanter.

FIG. 2 is a schematic explanatory view showing a belt type continuously variable transmission, a control device and the like.

FIG. 3 is an exploded perspective view showing a part of a transmission belt.

[Explanation of symbols]

 9 Drive side pulley 10 Load side pulley 11 Transmission belt 12 Endless elastic belt 16 Connection tool 23 Pickup sensor 24 Drive side rotation speed detection means 25 Belt rotation speed detection means 26 Speed difference detection means A Transmission piece

Claims (2)

[Claims] 1. A metal connector (1) comprising a large number of transmission pieces (A) arranged at a predetermined interval in the circumferential direction of an endless elastic belt (12).
In a belt type continuously variable transmission constituted by winding a transmission belt (11) connected to the endless elastic belt (12) around a driving pulley (9) and a load pulley (10) in 6), A pickup sensor (23) for electromagnetically detecting passage of the connecting tool (12) in the transmission belt (11).
A belt rotation speed that is arranged close to the winding path of the transmission belt (11) and is opposed thereto, and calculates the rotation speed of the transmission belt (11) based on the detection output from the pickup sensor (23). A belt-type continuously variable transmission equipped with detection means (25). 2. A connecting member (1) made of metal, comprising a large number of transmission pieces (A) arranged at predetermined intervals in the circumferential direction of an endless elastic belt (12).
In a belt type continuously variable transmission constituted by winding a transmission belt (11) connected to the endless elastic belt (12) around a driving pulley (9) and a load pulley (10) in 6), A pickup sensor (23) for electromagnetically detecting passage of the connecting tool (12) in the transmission belt (11).
A belt rotation speed that is arranged close to the winding path of the transmission belt (11) and is opposed thereto, and calculates the rotation speed of the transmission belt (11) based on the detection output from the pickup sensor (23). In addition to the detection means (25), a driving-side rotation speed detection means (24) for detecting the rotation speed of the driving-side pulley (9) is provided, and the driving-side rotation speed detection means (24) detects the rotation speed. Using the rotation speed as a reference rotation speed, a speed difference detecting means for calculating a difference between the reference rotation speed and the rotation speed of the transmission belt (11) detected by the belt rotation speed detecting means (25). A belt type continuously variable transmission including (26).