JPH0764408B2 - Endless chain multi-point simultaneous drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint simultaneous drive system for an endless chain used for carrying heavy objects such as mines in a mine laying ship.

As a device of this type, a drive sprocket is provided at one end of a long endless chain, and a driven sprocket is provided at the other end of the chain.
It is known that a caterpillar chain is provided at a plurality of positions in the middle of the going side (the side for carrying heavy goods), and a drive sprocket and a caterpillar chain are simultaneously driven by a hydraulic motor.

In this device, the load is shared by each drive unit so that the chain can be slackened in front of the drive sprocket. On the other hand, the return side of the chain (the side that does not carry the load)
Is a self-weight or spring type chain tension adjusting device, and it is common to plan a light tension to cope with chain wear.

When reversing such a device forward and reverse, especially in reverse,
Since the driven sprocket reversely transfers the heavy load via the spring of the tension adjusting device, the spring stretches and the chain largely sags, and the chain cannot be driven. In order to prevent this, a slack due to the weight of the chain is set during assembly and adjustment so that the chain can be rotated in the forward and reverse directions, but this often requires adjustment due to wear of the chain.

Moreover, when such a device is mounted on a ship, it is necessary to extend or contract the chain due to elastic strain of the hull.

A multi-point synchronous drive system has also been proposed in which the drive sprocket and the caterpillar chain are driven in synchronization with each other in order to take slack on the return side of the chain, but in this case, position control is performed for each drive point. It is necessary and a speed transmitter is required, which increases the cost.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a multi-point simultaneous drive device for an endless chain which is small in size, low in cost, and capable of forward and reverse rotation.

Means for Solving the Problems A multipoint simultaneous drive system for an endless chain according to the present invention is an endless chain for carrying a heavy load, a drive sprocket fixedly arranged at one end of the endless chain, and an endless chain. A driven sprocket that is movably arranged at the other end, a hydraulic ram that supports the driven sprocket and applies tension to the endless chain, a plurality of hydraulic motors that drive the drive sprocket and the intermediate part of the endless chain, and these The motor drive hydraulic circuit for driving the hydraulic motor and the hydraulic ram control device for controlling the pressure of the hydraulic ram to be a function of the high pressure side of the hydraulic circuit are provided.

Action Since the drive sprocket and the middle part of one end of the endless chain are driven simultaneously by multiple hydraulic motors,
The tension of the chain in each section between the plurality of driving points is reduced, and thus the chain can be downsized. Further, since the pressure of the hydraulic ram supporting the driven sprocket is controlled so as to be a function related to the high pressure side pressure of the motor drive hydraulic circuit of these hydraulic motors,
The slack in the chain during reverse rotation is reduced, therefore
Allows forward and reverse rotation of the chain.

Embodiment An embodiment in which the present invention is applied to a mine dropping device of a mine laying ship will be described below with reference to the drawings.

As shown in FIG. 1, the mine landing device comprises an endless chain (2) for carrying the mine (1). The endless chain (2) has a long loop shape in the fore-and-aft direction (front-back direction) in the vertical plane. The upper side is the forward side that carries the mine (1), and the lower side is the return side that does not carry the mine (1). Has become. A drive sprocket (3) is provided at the stern side (left side in FIG. 1) end of the endless chain (2).
However, a driven sprocket (4) is provided at the end of the bow side (right side in FIG. 1). Although not shown, the drive sprocket (3) is fixedly provided on the hull. The driven sprocket (4) is supported by a rod of a hydraulic ram (5) having a cylinder fixed to the hull. The hydraulic ram (6) presses the driven sprocket (4) toward the bow side by hydraulic pressure to apply tension to the chain (2).

A track chain (6) for driving the endless chain (2) is provided at a plurality of places (for example, three places) that equally divide the drive sprocket (3) and the driven sprocket (4) on the forward side of the chain (2). The drive point (A) is provided at four points where the drive sprocket (3) and the caterpillar chain (6) are provided. The driving points are collectively referred to by the symbol (A), and when it is necessary to distinguish them, the first driving point (A1), the second driving point (A2),
These are called the third driving point (A3) and the fourth driving point (A4). The forward side of the endless chain (2) is divided into four transfer sections (B) by a drive sprocket (3), a driven sprocket (4) and a caterpillar chain (6). These sections are collectively referred to by the code (B), and when it is necessary to distinguish them, the first section (B1), the second section (B2), the third section (B3), and the fourth section, in order from the latter one. (B4).

The drive sprocket (3) and the three caterpillar chains (6) respectively have a reduction gear (7a) (7b) (7c) (7).
It is connected via d) to the hydraulic motor with brake (8). These hydraulic motors are collectively referred to by the reference numeral (8), and when it is necessary to distinguish them, the first motor (8a), the second motor (8b), the third motor (8c), the fourth motor, in order from the latter one. We will call it the motor (8d). 4 hydraulic motors (8)
Is driven by one motor drive hydraulic circuit (9),
This hydraulic circuit (9) is controlled by the motor drive electric circuit (10) shown in FIG. This hydraulic circuit (9) controls the forward / reverse rotation of the hydraulic motor (8), that is, the endless chain (2), and controls the speed.
The two hydraulic motors (8) are driven in the same direction and at the same speed. The direction in which the forward side of the endless chain (2) moves from the front to the rear is forward rotation, and the opposite direction is reverse rotation.

The hydraulic ram (5) is connected to a motor drive hydraulic circuit (9) via a ram control hydraulic circuit (11). This hydraulic circuit (11) is controlled by the ram control electric circuit (12) of FIG. 3, and as described later, the pressure of the hydraulic ram (5) is controlled according to the high pressure side pressure of the motor drive hydraulic circuit (9). To be done. The ram control hydraulic circuit (11) and the same electric circuit (12)
The hydraulic ram control device is configured by the above.

As shown in FIG. 4, the endless chain (2) is a bush roller chain. The forward side of the endless chain (2) is guided by an upper chain rail (13) made of a pair of right and left groove-shaped members arranged in parallel so that the grooves face each other. The return side of the endless chain (2) is also guided by the same lower chain rail (14). In addition, the endless chain (2) has 1
A plurality of pairs of claws (15), which are one pair, are attached at equal intervals.

Just above the upper chain rail (13), mine rail (1
6) is provided. The mine rail (16) is composed of a pair of right and left groove-shaped members arranged in parallel so that the grooves face each other on the outside of the chain rail (13). Two wheels (17) are mounted on the left and right sides of the lower part of the mine (1), and these wheels (17) are guided to the mine rail (16). And 1 of the endless chain (2)
The lower middle part of the mine (1) in the left-right direction is sandwiched between the pair of claws (15) from the front and back, and by driving the endless chain (2) in such a state, the mine (1) is moved to the mine rail (16 ) To move back and forth.

The mine-laying ship is provided with an appropriate mine loading device, and by this, the mine (1) is carried into the front part of the mine rail (16) of the above-mentioned mine dropping device one by one. The mine (1) carried in the front part of the mine rail (16) is sent one by one by the forward rotation of the endless chain (2) and mounted on the mine rail (16). Mine rail (1
6) The mines (1) mounted on top are sent later by the forward rotation of the endless chain (2) and are dropped one by one from the rear end of the mines rail (16) into the sea. In some cases, the mine (1) mounted on the mine rail (16) may be forwarded by the reverse rotation of the endless chain (2) and may be unloaded one by one by the loading device.

Next, control of the hydraulic motor (8) and the hydraulic ram (5) when the endless chain (2) rotates in the forward direction will be described.

First, consider the case where there is a load on all four partitions (B). The load tension of the first section (B1) is W1, the second section (B2)
The load tension of W2, the load tension of the third section (B3) is W3, the fourth
The load tension of the section (B4) is W4, and they are all equal to W. In this case, since the loads of the four sections (B) are carried by the four hydraulic motors (8), the effective pressure ΔP acting on the hydraulic motors (8) is given by the following expression (1).

ΔP = 4 ・ W ・ R / 4 ・ Dm = W ・ R / Dm (1) where R is the sprocket radius and Dm is the hydraulic motor (8)
Is the discharge amount of.

Therefore, the high pressure side pressure PH1 of the hydraulic circuit (9) is expressed by the following equation (2).

PH1 = ΔP + PL (2) where PL is the boost pressure (low pressure side pressure). PL is kept at about 20 kgf / cm ² .

The load that was in the 1st section (B1) was carried out, and the 2nd and 3rd
And when considering the case where the load in the fourth section (B2) (B3) (B4) is transferred to the first, second and third sections (B1) (B2) (B3), the fourth section (B4) ) Has no load, so
Assuming that the endless chain (2) is stretched by the hydraulic ram (5) and has a predetermined tension, the fourth motor (8d) passes through the return side of the endless chain (2) to another hydraulic motor (8a) ( 8b) (8c) will be pulled. That is, the loads of the three sections (B1) (B2) (B3) are taken over by the four hydraulic motors (8). Therefore, PH1 is expressed by the following equation (3).

PH1 = (3/4) ΔP + PL (3) The load in the first section (B1) was carried out, and the loads in the second and third sections (B2) and (B3) were the first and second. Considering the case of being moved to the compartments (B1) (B2), there is no load in the third and fourth compartments (B3) (B4), so the loads of the two compartments (B1) (B2) are divided into four hydraulic pressures. The motor (8) will be responsible. Therefore, PH1 is expressed by the following equation (4).

PH1 = (1/2) ΔP + PL (4) When the load in the first section (B1) is carried out and the load in the second section (B2) is transferred to the first section (B1) Considering the second, third and fourth compartments (B2) (B3) (B
There is no load in 4), so load one section (B1) to 4
It will be handled by one hydraulic motor (8). Therefore, PH1 is expressed by the following equation (5).

PH1 = (1/4) ΔP + PL (5) When the load in the first section (B1) is carried out and the load disappears from all sections (B), PH1 is calculated as in the following equation (6). become.

PH1 = PL ...... (6) In order to satisfy the above formulas (2) to (6), the thrust of the hydraulic ram (5) acting on the driven sprocket (4) is adjusted and maintained at the necessary minimum. There is a need.

In the case of formula (2) in which there are loads in the four sections (B), W is applied as a load to each hydraulic motor (8), and the minimum tension (= 500 kg) is applied to the return side of the endless chain (2).
f) should work. Therefore, the thrust of the hydraulic ram (5) is 1000 (= 2 × 500) kgf (point X1 in FIG. 5).

In the case of formula (3) in which loads are applied to the three sections (B1), (B2), and (B3), the effective pressure of the hydraulic motor (8) is (3/4) ΔP, so the next chain tension F is driven. Acts on the sprocket (4).

F = (3/4) ΔP · Dm Therefore, the hydraulic ram (5) needs thrust of 2 · F = 1.5 · Dm · ΔP or more (point X2 in Fig. 5).

In addition, Dm · ΔP is the maximum tension of one section (B) (= 25
00kgf).

In the case of the expression (4) in which the two sections (B1) and (B2) are loaded, the two hydraulic motors (8) pull, so that the chain tension F acting on the driven sprocket (4) and the hydraulic ram (5) Thrust 2 · F is as follows (point X in Fig. 5)
3).

F = (1/2) ΔP ・ 2 ・ Dm = Dm ・ ΔP2 ・ F = 2.0 ・ Dm ・ ΔP In case of formula (5) with load in one section (B1), three hydraulic motors (8) Pulls, the chain tension F acting on the driven sprocket (4) and the hydraulic ram (5)
Thrust 2.F becomes as follows (point X4 in Fig. 5).

F = (1/4) ΔP · 3 · Dm = (3/4) Dm · ΔP 2 · F = 1.5 · Dm · ΔP In case of formula (6) where there is no load in any of the four sections (B) Since the minimum tension is 500 kgf, the thrust of the hydraulic ram (5) is 1000 (= 2 x 500) kgf (point X5 in Fig. 5).

Therefore, the relationship between the high-pressure side pressure PH1 of the motor drive hydraulic circuit (9) and the thrust of the hydraulic ram (5) in the normal rotation is as shown by the solid line in FIG.

Next, control of the hydraulic motor (8) and the hydraulic ram (5) when the endless chain (2) rotates in the reverse direction will be described.

First, if all four compartments (B) are loaded,
Further, since the one motor (8a) pulls the load of the fourth section (B4) through the driven sprocket (4), the chain tension acting on the driven sprocket (4) becomes F = Dm · ΔP and the hydraulic ram (5) ) Thrust force 2 · F is 2 · F = 2 · Dm · ΔP (point Y1 in Fig. 6).

The load in the 4th section (B4) was carried out, and the 3rd and 2nd
And if the load in the first section (B3) (B2) (B1) is transferred to the fourth, third and second sections (B4) (B3) (B2), F = (3/4) ΔP · Dm and 2 · F = 1.5 · Dm · ΔP (point Y2 in FIG. 6).

When the load that was in the fourth section (B4) was carried out and the load that was in the third and second sections (B3) and (B2) was transferred to the fourth and third sections (B4) and (B3) , F = (1/2) ΔP · 2 · Dm = Dm · ΔP and 2 · F = 2.0 · Dm · ΔP (point Y3 in FIG. 6).

When the load that was in the fourth section (B4) was carried out and the load that was in the third section (B3) was transferred to the fourth section (B4), F = (1/4) ΔP · 3 · Dm = (3/4) Dm · ΔP and 2 · F = 1.5 · Dm · ΔP (point Y4 in Fig. 6).

When there is no load on any of the four sections (B), the minimum tension is 500 kgf, so the thrust of the hydraulic ram (5) is 1000 kgf (point Y5 in FIG. 6).

Therefore, the relationship between the high pressure side pressure PH1 of the motor drive hydraulic circuit (9) and the thrust of the hydraulic ram (5) in the case of reverse rotation is as shown by the solid line in FIG.

Since the pressure PH2 of the hydraulic ram (5) is proportional to the thrust, the relationship between the pressure on the high pressure side of the motor drive hydraulic circuit (9) and the pressure of the hydraulic ram (5) is also as shown in FIGS. 5 and 6. The relationship shown in FIGS. 5 and 6 is set in the ram control electric circuit (12), and the pressure PH2 of the hydraulic ram (5) is controlled according to the high pressure side pressure PH1 of the motor drive hydraulic circuit (9). By doing so, the forward and reverse rotation of the endless chain (2) becomes possible. Since the relationship shown by the solid line in FIG. 6 is a little complicated, a part of it may be modified to be used as shown by the broken line.

In the above device, if the number of driving points (A) increases,
The chain tension of the driven sprocket (4) becomes larger than the drive tension of each drive point (A). The ratio of the chain tension of the driven sprocket (4) to the drive tension of each drive point is, for example, 1 times when the number of drive points is 4, 1.2 times when the number of drive points is 5, 1.5 times when the number of drive points is 6. Double, 1.7 for 7 points
Double, 8 points 2.0 times, 9 points 2.2 times, 10 points 2.5 times. Therefore, it is preferable to suppress the number of driving points to some extent.

Specific examples of the motor drive hydraulic circuit (9) and the electric circuit (10) and the ram control hydraulic circuit (11) and the electric circuit (12) will be described with reference to FIGS. 1 to 3. .

In the motor drive hydraulic circuit (9) of FIG. 1, (18) is an oil tank, (19) is a variable pump for driving the motor, and (20).
Is a boost pump that works with this. The variable pump (19) is connected to four hydraulic motors (8) via a forward / reverse switching valve (electromagnetic valve) (21). Forward / Reverse selector valve (21)
Are connected to the brakes (24) of the four hydraulic motors (8) via the brake valve (22) and the brake solenoid valve (23). The portion between the brake valve (22) and the brake solenoid valve (23) is connected to the discharge side of the boost pump (20). A first pressure detector (25) is provided on the discharge side of the variable pump (19), that is, on the high pressure side.
Reference numeral (26) is a tilting cylinder for controlling the discharge amount of the variable pump (19), which is connected to the pilot hydraulic pump (29) via the first servo valve (27) and the pressure reducing valve (28). . The tilt cylinder (26) is also provided with a potentiometer (30) for detecting the tilt angle.

When the endless chain (2) is not driven, the forward / reverse switching valve (21) is in the neutral position shown in FIG. 1 and no pressure oil is supplied to the hydraulic motor (8). The brake solenoid valve (23) is in the brake position (normal position) shown in Fig. 1, and the brake (24) is activated (turned on by a spring without supplying pressure oil to the brake (24). ), The hydraulic motor (8) is stopped.

When the endless chain (2) is driven, the solenoid valve (23) for braking is moved to the left side in FIG. 1 and switched to the brake release position on the right side in FIG. As a result, pressure oil is supplied to the brake (24), and the brake (2
4) is released (turned off) and the hydraulic motor (8) becomes rotatable.

When the endless chain (2) is rotated in the forward direction, the forward / reverse switching valve (21) is moved to the right side in FIG. 1 and switched to the forward rotation position on the left side in FIG. This causes the hydraulic motor (8) to rotate normally, and the endless chain (2) to rotate normally.

When reversing the endless chain (2), the forward / reverse switching valve (21) is moved to the left side in FIG. 1 and switched to the reverse position on the right side in FIG. This causes the hydraulic motor (8) to rotate in the reverse direction and the endless chain (2) to rotate in the reverse direction.

The motor drive electric circuit (10) of FIG. 2 includes a speed setting circuit (31), a servo amplifier circuit (32) and the like. Based on the speed setting voltage from the speed setting circuit (31) and the output signal of the potentiometer (30) of the tilt cylinder (26),
The servo amplifier circuit (32) controls the first servo valve (27),
As a result, the variable pump (19) is controlled and the endless chain (2) is driven at a constant speed.

A flushing valve (33) and a flow control valve (34) are connected to the variable pump (19). Flushing valve (3
3) is for returning a part of the high temperature oil in the closed circuit between the variable pump (19) and the hydraulic motor (8) to the tank (18), and the flow control valve (34) is closed. It is for determining the amount of oil exchange in the circuit.

In the ram control hydraulic circuit (11) of FIG. 1, (35) is a second servo valve, and (36) is a tension holding solenoid valve. The second servo valve (35) and the solenoid valve (36) are connected to the pressure reducing valve (28) and the tank (18) of the motor drive hydraulic circuit (9). A pilot check valve (37) is provided between the second servo valve (35) and the hydraulic ram (5), and a piston accumulator (38) is provided between the check valve (37) and the hydraulic ram (5). ) Is connected. Solenoid valve (36)
It is connected to the pilot port of the check valve (37). The hydraulic ram (5) also has a second pressure detector (39).
Is provided.

When the endless chain (2) is not driven, the solenoid valve (36) is in the pilot pressure inoperative position (normal position) shown in Fig. 1 and the pilot pressure does not act on the check valve (37), so the hydraulic pressure The reverse flow of oil from the ram (5) side to the second servo valve (35) side is blocked. The hydraulic ram (5) is kept at a predetermined pressure by the accumulator (3B), and a predetermined tension is applied to the endless chain (2) via the driven sprocket (4).

When driving the endless chain (2), the solenoid valve (36) is moved to the left side in FIG. 1 and switched to the pilot pressure acting position on the right side in FIG. This allows
Pilot pressure acts on the check valve (37), allowing backflow. Then, as described below, the pressure of the hydraulic ram (5) is controlled by controlling the second servo valve (35), and as a result, the chain tension of the driven sprocket (4) is controlled. .

The Ram control electric circuit (12) of FIG. 3 comprises a low pass filter (LPF) (40), two function generators (41), (42), a servo amplifier circuit (43), and the like. The output signal of the first pressure detector (25) of the motor drive hydraulic circuit (9) is sent to the low pass filter (40) to remove high frequency components such as pressure transients. The output of the low pass filter (40) is
It represents the high pressure side pressure PH1 of the closed circuit of the motor drive hydraulic circuit (9). The first function generator (4) outputs the command value of the pressure PH2 of the hydraulic ram (5) from the output PH1 of the low pass filter (40) based on the normal rotation relationship in FIG.
The second function generator (42) outputs the command value of the pressure PH2 of the hydraulic ram (5) from the output PH1 of the low pass filter (40) based on the relationship at the time of reverse rotation in FIG. The first function generator (41) is used during normal rotation of the endless chain (2), and the second function generator (42) is used during reverse rotation. Then, the command value of the pressure PH2 from the function generators (41) (42) and the second
Based on the detection signal of pressure PH2 from the pressure detector (39),
The servo amplifier circuit (43) controls the second servo amplifier valve (35), so that the pressure in the hydraulic ram (5) becomes a function of pressure PH1 as shown in FIG. At times, it is controlled to be a function of the pressure PH1 as shown in FIG.

EFFECTS OF THE INVENTION According to the multipoint simultaneous drive system for an endless chain of the present invention, as described above, the chain can be downsized, and one motor drive hydraulic circuit and the hydraulic ram control device can rotate the chain forward and backward. Become. For this reason, the conventional position control for each drive point and the speed transmitter are not required, and the device can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a multipoint simultaneous drive system for an endless chain showing an embodiment of the present invention, FIG. 2 is a block diagram showing a motor drive electric circuit, and FIG. 3 is a block diagram showing a ram control electric circuit. FIG. 4 is a cross-sectional view showing an endless chain and a mine portion, and FIG. 5 is a graph showing the relationship between the pressure on the high-pressure side of the hydraulic motor and the pressure of the hydraulic ram during forward rotation.
The figure is a graph showing the relationship between the pressure on the high-pressure side of the hydraulic motor and the pressure on the hydraulic ram during reverse rotation. (1) ... mine, (2) ... endless chain, (3) ...
Drive sprocket, (4) ... driven sprocket, (5)
… Hydraulic ram, (8a) (8b) (8c) (8d)… Hydraulic motor,
(9) ... Motor drive hydraulic circuit, (10) ... Motor drive electric circuit, (11) ... Ram control hydraulic circuit, (12) ... Ram control electric circuit.

Claims (1)

[Claims] 1. An endless chain for conveying a heavy load, a drive sprocket fixedly arranged at one end of the endless chain, a driven sprocket movably arranged at the other end of the endless chain, and a driven follower. A hydraulic ram that supports the sprocket and applies tension to the endless chain, a plurality of hydraulic motors that drive the drive sprocket and the middle part of the endless chain, a motor drive hydraulic circuit that drives these hydraulic motors, and A multi-point simultaneous drive system for an endless chain, comprising: a hydraulic ram control device that controls the pressure of the hydraulic ram to be a function of the high-pressure side pressure.