JP3703659B2 - Belt tension mechanism of snowplow - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a belt tension mechanism of a snowplow.
[0002]
[Prior art]
For example, a belt tension mechanism (belt tension clutch mechanism) widely used in snowplows is clearly shown in FIG. 1 of Japanese Patent Application Laid-Open No. 63-223207, “Small Snowplow”. That is, in FIG. 1, the belt 18 is wound around the drive pulley 17 (the reference numeral is the same as that in the publication), and the driven pulley 16 and the operation wire 67 is pulled to bring the swing arm 47 into the arrow B side. The roller 46 at the tip is pushed out as shown by the arrow B, the belt 18 is tensioned, and the driving force of the driving pulley 17 is transmitted to the driven pulley 16. When the operation wire 67 is loosened, the swinging arm 47 swings in the direction of arrow A due to the return action of the plurality of springs, and the roller 46 moves as indicated by arrow A. Therefore, the belt 18 is loosened, and the driving force of the driving pulley 17 is It will not be transmitted to the driven pulley 16.
[0003]
Since the transmission of the driving force is “on / off”, it is called a belt tension clutch mechanism, but is abbreviated as a belt tension mechanism here.
The operation wire 67 is manually operated by the travel lever 40 shown in FIG. 5 of the publication.
[0004]
[Problems to be solved by the invention]
In the snowplow, the driver turns on and off the travel clutch lever and the auger drive lever to determine whether or not to “run” by turning the driving wheel and “snow removal” by turning the auger. In addition, the driver must visually check the snow situation and check the surrounding situation, which is a heavy operational burden. In particular, if you forget to turn off the travel clutch lever or auger drive lever, the belt will continue to be pushed by the roller and the belt will be extended, so to maintain the belt life properly, when stopping or stopping the snowplow Operation of the travel clutch lever and auger drive lever is indispensable. This increases the burden on the driver at the end of work.
[0005]
Therefore, an object of the present invention is to provide a belt tension mechanism for a snowplow that can reduce the burden on the driver at the end of work.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a snow removal power transmission system that transmits engine power to the auger and blower and a traveling power transmission system that transmits engine power to the drive wheels. A belt is installed across these belts, and power is transmitted by increasing the tension of the belt by pressing the tension roll, and by removing the tension roll, the belt tension is lowered and the power is not transmitted. In the belt tension mechanism, the belt tension mechanism includes a return member that returns the tension roll, a tensioner member that uses the electric motor as a drive source and presses the tension roll against the belt against the return action of the return member, and the engine switch is turned off. Tension roll by reversing the electric motor based on the information Back e Preparations and a control unit for controlling the electric motor so as to loosen the belt, and a coil spring as a compression spring, a first tension member attached to one end of the coil spring through the coil spring, the coil A tension spring unit comprising: a second tension member surrounding the spring and attached to the other end of the coil spring; and a first switch means attached to the second tension member for detecting the amount of compression of the coil spring. It is provided with the 2nd switch means interposed in a tensioner member and detecting directly the clutch lever returned by the return member .
[0007]
Based on the information that the engine switch is turned off, the electric motor is reversed to return the tension roll to loosen the belt.
When the engine is stopped, the tension roll automatically returns and the belt is loosened, so that the burden on the driver at the end of work is lightened.
[0009]
When the coil spring is contracted by a certain amount, it is detected by the switch means and the electric motor is stopped. Since the coil spring and the switch means are mounted on the second tension member, even if the belt becomes old and the permanent extension becomes remarkable, a constant tension can be applied without adjusting the position of the switch means.
Therefore, a constant tension can always be applied to the belt, and the life of the belt can be maintained appropriately.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a snowplow according to the present invention. A snowplow 10 includes a crawler frame 16 provided with a free wheel 11 at a front portion and three lower rolling wheels 12, 13, and 14 at a lower portion, respectively. A vehicle body frame 21 is connected to the rear portion so as to be able to swing up and down, a snow removing portion 30 as a work tool is attached to the front portion of the vehicle body frame 21, an engine 22 is mounted on the vehicle body frame 21, and driving wheels are mounted on the rear portion of the vehicle body frame 21. 23, a crawler belt 24 is wound around the drive wheel 23 and the idler wheel 11, the pivot shaft 25 connecting the vehicle body frame 21 to the crawler frame 16 is moved forward, the drive wheel 23 is moved rearward, and the rear lower roll is rotated. The wheel 14 is disposed below the middle of the pivot shaft 25 and the drive wheel 23, and the upper roller 26 that supports the crawler belt 24 above the middle of the pivot shaft 25 and the drive wheel 23 is disposed on the crawler frame. It is a crawler type vehicle, characterized in that attached to the 6.
[0011]
The snow removal unit 30 includes an auger 31, a blower 32, a snow removal unit housing 33, a sled 34, and a shooter 35 which are driven by the engine 22 as basic elements. The engine 22, a small diameter pulley 36, a belt 37, a large diameter pulley 38, a drive shaft. 39, the gear case 41, and the auger shaft 42 are transmitted in the order of the engine 22 to rotate the auger 31 and scrape the snow on the road in the direction of the front and back of the drawing to send it to the blower 32. Project snow through 35. Reference numeral 43 denotes an engine cover, 44 an engine air cooling fan, 45 an output pulley connected to the drive wheel 23, and 50 an auger height adjusting hydraulic cylinder.
[0012]
2 is a cross-sectional view taken along line 2-2 of FIG. 1, and shows a belt tension mechanism provided in a snow removal power transmission system that transmits engine power to an auger and a blower. The belt tension mechanism 60 acts on a belt 37 wound around a small-diameter pulley 36 and a large-diameter pulley 38, and includes a tension roll 62 attached to a clutch lever 61 and a return member for returning the tension roll 62. The return spring 63 and the electric motor 64 are used as a drive source, the tensioner member 65 that presses the tension roll 62 against the belt 37 against the return action of the return spring 63, and the information based on the information that the engine switch 66 is turned off. It comprises a controller 67 that controls the electric motor 64 so as to reverse the motor 64 and return the tension roll 62 to loosen the belt 37. 68 is a clutch switch.
[0013]
For example, the tensioner member 65 includes a tension rod 71 connected to the clutch lever 61, a tension spring 72 connected to the other end of the tension rod 71, a wire 73 connected to the other end of the tension spring 72, and the wire. 73, and a gear set 75 that rotates the drum 74. When the electric motor 64 is rotated forward by receiving power from the battery 76, the drum 74 is rotated forward via the gear set 75 and the wire 73 is rotated. The tension rod 71 is pulled, the clutch lever 61 indicated by the imaginary line is rotated clockwise, and the belt 37 is tensioned by the tension roll (solid line) 62. The forward rotation of the electric motor 64 continues until the pin 77 extended from the tension rod 71 is detected by the first switch means 78.
[0014]
The operation of loosening the belt 37 is as follows.
Receiving information that the engine switch 66 has been turned off, the control unit 67 issues a reverse rotation command to the motor rotation direction control unit 79, and the motor rotation direction control unit 79 reverses the positive / negative polarity to reverse the electric motor 64. Since the wire 73 and the tension rod 71 are in the loose state, the pulling action of the return spring 63 is effective, and the clutch lever 61 and the tension roll 62 indicated by the solid line return to the position of the imaginary line, and the belt 37 is in the loose state. The second switch means 81 detects that the clutch lever 61 has returned, and the control unit 67 stops the operation (reverse rotation) of the electric motor 64 based on this detection signal.
[0015]
FIG. 3 is a control flowchart of the belt tension mechanism according to the present invention, and STxx indicates a step number.
ST01: Check whether the main switch is on. If YES, the process proceeds to the next step, and if NO, the process proceeds to ST05.
ST02: Check whether or not the clutch switch is on. If YES, proceed to the next step, and if NO, do not proceed to the next step.
ST03: Check whether or not the first switch means (SW1) is on.
ST04: The electric motor is normally rotated when NO in ST03. This forward rotation is continued until SW1 is turned on in ST03.
[0016]
ST05: In ST01, when the main switch is not on, that is, in the off state, it is checked whether or not the second switch means (SW2) is on.
ST06: Reverse the electric motor when NO in ST05. This reverse rotation is continued until SW2 is turned on in ST05.
According to ST01, ST05, ST06, when the main switch is switched from on to off, the belt is automatically returned to the loose state.
[0017]
In other words, the driver can adjust the belt tension without manually operating the clutch, and the belt is automatically loosened in conjunction with the main switch being turned off. Therefore, the life of the belt can be extended sufficiently.
[0018]
FIG. 4 is a diagram showing another embodiment of FIG. 2, and the same parts as those in FIG. This another embodiment is characterized in that the tension rod 71 and the wire 73 are connected by a tension spring unit 90.
[0019]
FIG. 5 is an explanatory view of a tension spring unit employed in another embodiment. The tension spring unit 90 includes a coil spring 91 as a compression spring and one end of the coil spring 91 that passes through the coil spring 91 (the left end in the figure). A first tension member 92 attached to the coil spring 91, a second tension member 93 surrounding the coil spring 91 and attached to the other end (right end in the figure) of the coil spring 91, and a second tension member for detecting the amount of compression of the coil spring 91. And first switch means 78 attached to the member 93.
[0020]
The first tension member 92 is, for example, a rod provided with a flange 94 at the base and a screw 95 at the tip, and the second tension member 93 is formed by bending the strip plate into an oval shape so as to surround the coil spring 91, for example. Is.
The coil spring 91 is set in the space surrounded by the second tension member 93, the first tension member 92 is inserted into the hole 96 of the second tension member 93, and the nut 97 is screwed into the screw 95 of the first tension member 92. The initial length H of the coil spring 91 is determined. Further, the first switch means 78 is attached at a position where the tip of the coil spring 91 is desired.
Then, the wire 73 is fixed to the base portion of the first tension member 92, and the tension rod 71 is attached to the second tension member 93.
[0021]
When tension is applied to the wire 73 and the tension rod 71, the tension rod 71 and the second tension member 93 move relatively to the left in the figure, and the wire 73 and the first tension member 92 move relatively to the right in the figure. The coil spring 91 contracts.
When the coil spring 91 is contracted to the length h1, this is detected by the first switch means 78. At this time, the acting tension F is k · h1 (k is a spring constant).
The advantages of the tension spring unit 90 having such a structure will be described next.
[0022]
6 (a) to 6 (d) are operation diagrams and comparison diagrams of the tension spring unit employed in another embodiment, (a) and (b) are operation diagrams of FIG. 4, and (c) and (d) are FIG. FIG. 3 is an operation diagram of FIG. 2.
(A) shows a state where a new belt 37 is tensioned by a tension roll 62 via a tension spring unit 90 in another embodiment (with a tension spring unit 90).
(B) shows a state where an old belt 37 is tensioned by a tension roll 62 via a tension spring unit 90 in another embodiment (with a tension spring unit 90).
Since the tension can be kept constant by the tension spring unit 90, the belt 37 can be tensioned regardless of the secular change of the belt 37.
[0023]
(C) shows a state in which the new belt 37 is tensioned by the tension roll 62 via the tension spring 72 in the embodiment (without the tension spring unit).
(D) shows a state in which the old belt 37 is tensioned by the tension roll 62 via the tension spring 72 in the embodiment (without the tension spring unit), but the first switch means 78 is as indicated by an arrow (3). The position must be adjusted.
[0024]
That is, in (c) and (d), the first switch means 78 is mounted on the airframe side, while the position of the pin 77 of the tension rod 71 changes according to the permanent extension of the belt 37. The position must be adjusted accordingly. On the other hand, the structure is simple.
[0025]
On the other hand, (a) and (b) are characterized in that the first switch means 78 is mounted on the second tension member 93 and that the coil spring 91 is a compression spring. 2 Since the tension member 93, the coil spring 91 and the first switch means 78 move together, it is not necessary to adjust the position of the first switch means 78.
In addition, as described with reference to FIG. 5, the tension acting on the belt 37 is always constant, and the life of the belt 37 can be greatly extended.
[0026]
The belt tension mechanism 60 described above can also be applied to a traveling power transmission system from the output pulley 45 to the drive wheels 23 in FIG.
In the tension spring unit 90 of FIG. 5, the tension rod 71 may be coupled to the first tension member 92 and the wire 73 may be coupled to the second tension member 93. Therefore, the attachment posture of the tension spring unit 90 is arbitrary.
Furthermore, the shapes of the first and second tension members 92 and 93 are arbitrary.
[0027]
In addition, although the full crawler belt type snow removal machine was demonstrated in the Example, it may be a tire type snow removal machine, a snow removal machine combining a half crawler and a ski, or a snow removal machine combining a half crawler and a tire. The specific configuration of is arbitrary.
[0028]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
The first aspect reverses the electric motor based on the information that the engine switch is turned off to return the tension roll to loosen the belt. When the engine is stopped, the tension roll automatically returns and the belt is loosened, so that the burden on the driver at the end of work is lightened.
[0029]
In addition, according to the first aspect of the present invention, when the coil spring is contracted by a certain amount, it is detected by the switch means and the electric motor is stopped. Since the coil spring and the switch means are mounted on the second tension member, even if the belt becomes old and the permanent extension becomes remarkable, a constant tension can be applied without adjusting the position of the switch means.
Therefore, a constant tension can always be applied to the belt, and the life of the belt can be maintained appropriately.
[Brief description of the drawings]
FIG. 1 is a side view of a snowplow according to the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. 1. FIG. 3 is a control flow diagram of a belt tension mechanism according to the present invention. Example diagram [FIG. 5] Explanatory drawing of a tension spring unit adopted in another embodiment [FIG. 6] Action diagram and comparison diagram of a tension spring unit adopted in another embodiment [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Snow remover, 22 ... Engine, 23 ... Drive wheel, 31 ... Auger, 32 ... Blower, 36, 38 ... A pair of pulley, 37 ... Belt, 60 ... Belt tension mechanism , 61 ... Clutch lever , 62 ... Tension roll, 63 ... Return member (return spring), 64 ... Electric motor, 65 ... Tensioner member, 66 ... Engine switch, 67 ... Control part, 78 ... First switch means, 81 ... Second switch means, 90 ... Tension spring unit, 91 ... Coil spring, 92 ... First tension member, 93 ... Second tension member.

Claims (1)

A pair of pulleys and a belt that spans these belts are installed in either or both of the snow removal power transmission system that transmits engine power to the auger and blower and the traveling power transmission system that transmits engine power to the drive wheels. In the belt tension mechanism of a snowplow that transmits power by increasing the belt tension by pressing the roll, and lowering the belt tension and returning power by returning the tension roll,
This belt tension mechanism is based on a return member that returns a tension roll, a tensioner member that uses an electric motor as a drive source and presses the tension roll against the belt against the return action of the return member, and information that the engine switch is turned off. Bei example and a control unit that is reversed to control the electric motor so as to loosen the belt to return the tension roll the electric motor Te,
A coil spring as a compression spring; a first tension member that passes through the coil spring and is attached to one end of the coil spring; a second tension member that surrounds the coil spring and is attached to the other end of the coil spring; and the coil A tension spring unit comprising a first switch means attached to a second tension member for detecting the amount of compression of the spring, and interposed in the tensioner member;
A belt tension mechanism for a snow machine, comprising second switch means for directly detecting the clutch lever returned by the return member .

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