JP2016222380A - Brake device of winch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve brake operability and suppress deterioration in cooling performance, regardless of a change in flow rate of cooling oil.SOLUTION: A brake device of a winch includes a wet multiple disk brake which has an inlet into which cooling oil passing between a plurality of friction plates is introduced and an outlet from which the cooling oil is discharged. The wet multiple disk brake includes: a pressing member for generating brake force by bringing the friction plates into pressure-contact with each other; a pressure-contact force adjustment device for adjusting the pressure-contact force of the friction plates each other by applying driving force to the pressing member; a working force control device for controlling force applied to the pressing member, which is force other than the driving force applied to the pressing member, so that force for increasing the pressure-contact force of the friction plates each other and force for decreasing the pressure-contact force are balanced.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a winch brake device.

  2. Description of the Related Art Conventionally, there is known a wet multi-plate brake including a rotary friction plate that can be driven to rotate, a fixed friction plate, and a pressing member that presses the rotary friction plate and the fixed friction plate against each other by a biasing force of a spring (Patent Document). 1). In the wet multi-plate brake, a pressure loss occurs when cooling oil flows between a plurality of friction plates, and a differential pressure is generated on both surfaces of the pressure plate constituting the pressing member due to the pressure loss. The differential pressure affects the brake operability.

  In Patent Document 1, attention is paid to the fact that the amount of cooling oil changes and the pressure loss changes as the engine rotational speed changes, and the increase in pressure loss accompanying the increase in the rotational speed of the engine that drives the cooling oil pump is disclosed. In order to limit this, a winch brake device that regulates the upper limit of the pressure on the inlet side of the cooling oil is disclosed.

JP 2003-285993 A

  However, in the technique described in Patent Document 1, when the engine speed increases and the relief valve provided on the discharge side of the cooling oil pump exceeds the relief set pressure, a part of the discharge oil of the cooling oil pump causes the relief valve to It is the structure bypassed through. Therefore, in a state before the relief valve is operated, there is a problem that the influence of the pressure of the cooling oil in the casing on the brake operability cannot be reduced. In the technique described in Patent Document 1, since the cooling oil is actively bypassed to reduce pressure loss, the amount of cooling oil introduced into the brake is reduced by the amount of the bypassed cooling oil. As a result, the cooling performance may be reduced.

  The winch brake device according to claim 1 is a winch brake device including a wet multi-plate brake having an inlet through which cooling oil passing between a plurality of friction plates is introduced and an outlet through which the cooling oil is discharged. The wet multi-plate brake includes a pressing member that presses the friction plates together to generate a braking force, a pressing force adjusting device that adjusts the pressing force between the friction plates by applying a driving force to the pressing member, and a pressing member. An acting force control device that controls a force acting on the pressing member so as to balance a force other than the acting driving force that increases the pressure contact force between the friction plates and the force that decreases the force.

  According to the present invention, the brake operability can be improved and the cooling performance can be prevented from being lowered regardless of the change in the flow rate of the cooling oil (that is, even when the flow rate of the cooling oil is small). .

The external appearance side view of the crane provided with the brake device which concerns on 1st Embodiment. The hydraulic circuit diagram which shows the structure of the winch apparatus which has a brake device which concerns on 1st Embodiment. The figure which shows the structure of the brake which concerns on 1st Embodiment. (A) is the schematic diagram which looked at the rotating friction board from the axial direction, (b) is the EE sectional view schematic diagram of (a). The schematic diagram which showed typically the distributed pressure which generate | occur | produces when cooling oil passes between friction plates. The hydraulic circuit diagram which shows the structure of the winch apparatus which has a brake device which concerns on 2nd Embodiment. The figure which shows the structure of the brake which concerns on 2nd Embodiment. The figure which shows the structure of the brake which concerns on 3rd Embodiment.

Hereinafter, an embodiment of a crane provided with a brake device according to the present invention will be described with reference to the drawings.
-First embodiment-
FIG. 1 is an external side view of a crane provided with a brake device according to a first embodiment of the present invention. The crane 100 includes a traveling body 101, a revolving body 103 that is turnable on the traveling body 101, and a boom 104 that is pivotally supported by the revolving body 103. The revolving structure 103 is equipped with a hoisting winch 105 which is a winch for hoisting and a hoisting winch 106 which is a winch for raising and lowering a boom.

  A hoisting rope 105 a is wound around the hoisting winch 105, and the hoisting rope 105 a is wound or fed out by the rotation of the hoisting winch 105, and the hook 110 moves up and down. The hoisting rope 106 a is wound around the hoisting winch 106, and the hoisting rope 106 a is wound or fed out by the rotation of the hoisting winch 106, and the boom 104 is raised and lowered.

  FIG. 2 is a hydraulic circuit diagram showing the configuration of the winch device having the brake device according to the first embodiment of the present invention. In FIG. 2, the hydraulic circuit that drives the hoisting winch 105 is illustrated, and the hydraulic circuit that drives the hoisting winch 106 is not illustrated. The crane 100 includes a controller 18 that controls the operation of each part of the crane 100, an engine (not shown), a main pump 12, a cooling oil pump 19, and a pilot pump 9 that are driven by the engine (not shown). . The main pump 12, the cooling oil pump 19 and the pilot pump 9 discharge the hydraulic oil in the tank 10 as pressure oil.

  The winch device includes a winding drum 3, a hydraulic motor 1, a main pump 12, a control valve 11, a planetary reduction mechanism 2, and a brake device B. The main pump 12 supplies pressure oil to the hydraulic motor 1 and drives the hydraulic motor 1 to drive the winding drum 3 to wind up and down. The control valve 11 controls the flow of pressure oil from the main pump 12 to the hydraulic motor 1. The planetary reduction mechanism 2 transmits the driving force of the hydraulic motor 1 to the winding drum 3. The brake device B prevents free rotation of the winding drum 3 by braking the carrier shaft 4 i of the planetary reduction mechanism 2.

  The brake device B includes a brake 4 mounted in the winding drum 3. The brake 4 is a wet multi-plate brake having a plurality of friction plates, and includes a pressing member 4p that presses the friction plates together to generate a braking force. The brake device B includes a pressing force adjusting device that adjusts the pressing force between the friction plates by applying a driving force to the pressing member 4 p of the brake 4.

  The pressing force adjusting device applies a driving force to the pressing member 4p so as to reduce a pressing force between the friction plates and a spring 4f that applies a driving force to the pressing member 4p so as to increase the pressing force between the friction plates. And a hydraulic cylinder device.

  That is, the brake device B of the present embodiment generates a braking force by the biasing force of the spring (elastic member) 4f, and the brake is released by applying the brake release pressure to the hydraulic cylinder device. It is. The brake device B also has a function as a clutch device that transmits and shuts off rotation between the hydraulic motor 1 and the winding drum 3.

  The hydraulic circuit for driving the winch is switched by the controller 18 by the motor brake switching valve 7 that is controlled to be switched by the operation of the winch operating lever 13, the motor brake cylinder 8, the brake control valve 6 that is operated by the brake pedal 6a, and the controller 18. A brake switching valve 5 to be controlled and a cooling circuit safety valve 20 are provided. Further, in this hydraulic circuit, an operation pressure sensor 15 and a brake circuit pressure sensor 16 are provided to switch the operation mode of the brake 4 by switching the brake switching valve 5 and are connected to the controller 18, respectively. Further, a brake mode changeover switch 17 is connected to the controller 18. The operation mode of the brake 4 is switched to an automatic brake mode, which will be described later, or a neutral free mode.

  The planetary reduction mechanism 2 includes a sun gear 2a, a planetary gear 2b, and a ring gear 2c. The output shaft of the hydraulic motor 1 is connected to the sun gear 2 a of the planetary reduction mechanism 2. A planetary gear 2b is meshed with the sun gear 2a, and a ring gear 2c provided on the inner peripheral side of the take-up drum 3 is meshed with the planetary gear 2b. The planetary gear 2b is supported by the planetary carrier 2d, and the carrier shaft 4i to which the planetary carrier 2d is fixed penetrates the side wall (first end plate 4g3 described later) of the casing 4g of the brake 4 and reaches the brake 4. The carrier shaft 4i is supported by a bearing, and an oil seal 4h seals between the outer peripheral surface of the carrier shaft 4i and a through hole through which the carrier shaft 4i is inserted. For convenience of explanation, the rotation axis direction of the hoisting winch 105, that is, the center axis direction of the carrier shaft 4i is simply referred to as an axial direction in the following description.

  The casing 4g includes a first cylindrical portion 4g1 in which a plurality of friction plates are disposed on the inner side, a second cylindrical portion 4g2 in which the pressing member 4p is disposed on the inner side, and a first end that closes the opening end of the first cylindrical portion 4g1. It has plate 4g3 and 2nd end plate 4g4 which plugs up the opening end of 2nd cylinder part 4g2. The first cylinder part 4g1 and the second cylinder part 4g2 are combined and integrated, and an accommodation space for accommodating each component of the brake 4 is formed inside the casing 4g.

  FIG. 3 is a diagram showing a configuration of the brake 4 according to the first embodiment. 3A schematically shows a state where the friction plates are pressed against each other and a braking force is generated, and FIG. 3B schematically shows a state where the friction plates are separated from each other and no braking force is generated. Is shown. A sliding chamber 140, a carrier shaft chamber 141, a disk chamber 142, an outer peripheral flow path 144, and a spring chamber 143 are formed in the housing space of the casing 4g.

  The sliding chamber 140 is a space in which a first sliding portion 4t provided at the tip of a piston portion 4e described later is accommodated. The carrier shaft chamber 141 is a space on the inner peripheral side of the disk chamber 142, and is a space in which an end portion of the carrier shaft 4i is accommodated. The disk chamber 142 is a space in which a plurality of annular friction plates (rotating friction plates 4a and fixed friction plates (mating plates) 4b) are accommodated. The outer peripheral channel 144 is a space arranged on the outer peripheral side of the disk chamber 142. The spring chamber 143 is a space in which the spring 4f is accommodated. The carrier shaft chamber 141 communicates with the outer peripheral flow path 144 via the disk chamber 142, and the outer peripheral flow path 144 communicates with the spring chamber 143. The spring chamber 143 communicates with an outlet port 4k provided in the second end plate 4g4, and the outlet port 4k is connected to the tank 10 (see FIG. 2).

  The rotating friction plates 4 a and the fixed friction plates 4 b are alternately arranged in the axial direction in the disk chamber 142. A plurality of rotating friction plates 4a are engaged with the carrier shaft 4i so as to be movable in the axial direction by spline coupling, and the rotating friction plates 4a can rotate integrally with the carrier shaft 4i.

  A plurality of fixed friction plates 4b are engaged with the inner peripheral surface of the casing 4g so as to be movable in the axial direction by spline coupling. The fixed friction plates 4b are connected by a coil spring 4c. For this reason, in the brake release state, the fixed friction plates 4b move so as to be separated from each other, and a gap is formed between the rotating friction plate 4a and the fixed friction plate 4b (see FIG. 3B). A clearance is formed between the rotating friction plate 4a and the fixed friction plate 4b, so that drag torque during free fall (rotational resistance due to the viscosity of oil between the rotating friction plate 4a and the fixed friction plate 4b (so-called drag) Torque)) is reduced. In the present specification, the rotary friction plate 4a and the fixed friction plate 4b are also collectively referred to as a friction plate (brake disc).

4A is a schematic view of the rotating friction plate 4a viewed from the axial direction, and FIG. 4B is a schematic cross-sectional view taken along the line EE of FIG. 4A. In the present embodiment, as shown in FIG. 4, annular friction materials 148 having an outer diameter D ₁ and an inner diameter D ₂ are attached to both surfaces of the rotating friction plate 4a, and the friction material of the rotating friction plate 4a. As a result of the pressure contact between 148 and the fixed friction plate 4b, a braking force (braking force) is generated by the friction between the rotating friction plate 4a and the fixed friction plate 4b. The friction material 148 has a lattice-shaped groove 149 so that the cooling oil flows between the friction plates via the groove 149 even when the rotating friction plate 4 a and the fixed friction plate 4 b are in pressure contact with each other. become.

  As shown in FIG. 3, a pressing member 4p is disposed between the end of the carrier shaft 4i and the second end plate 4g4 of the casing 4g. The pressing member 4p has a pressure plate 4d and a piston portion 4e fixed to the pressure plate 4d. The pressure plate 4d is disposed between the spring 4f and the friction plate so as to divide the spring chamber 143 and the disk chamber 142.

  The pressure plate 4d has a disk-like base 4q to which the piston 4e is fixed, and a pressing portion 4r extending radially outward from the base 4q. The base portion 4q is provided with a circular fitting hole penetrating in the axial direction, and one end portion of the piston portion 4e is fitted and fixed to the fitting hole, so that the piston portion 4e and the pressing member 4p Are joined together.

The pressing portion 4r has a pressing surface 4r1 that comes into contact with the fixed friction plate 4b. Pressing surface 4r1 is an annular plane, an inner diameter is the same size D ₂ to the inner diameter of the friction member 148 of the rotating friction plate 4a, an outer diameter equal to the outer diameter of the friction member 148 of the rotating friction plate 4a is sized _{D 1 (D 1> D 2} ). A spring 4f is disposed between a surface of the pressing portion 4r opposite to the pressing surface 4r1 and a receiving surface provided on the second cylindrical portion 4g2 of the casing 4g. The spring 4f is an elastic member that urges the pressing member 4p in the axial direction toward the friction plate by an elastic force.

The piston part 4e is a cylindrical member provided coaxially with the carrier shaft 4i, and has an internal flow path through which cooling oil passes. As described above, one end of the piston portion 4e is fixed to the pressure plate 4d. The piston portion 4e is provided with a first sliding portion 4t at the other axial end portion and a second sliding portion 4s at the axial center. Outer diameter _{D 3} of the first sliding portion 4t is larger than the outer diameter _{D 4} of the second sliding portion _{4s (D 3> D 4)} .

  The sliding chamber 140 in which the first sliding portion 4t is accommodated is defined by a circular concave portion provided in the second cylindrical portion 4g2 and the second end plate 4g4, and a second sliding portion 4s is formed at the bottom of the circular concave portion. Is provided with a circular through-hole 145 that is slidably inserted in the axial direction.

  In the sliding chamber 140, the first sliding portion 4t is slidably disposed in the axial direction. The sliding chamber 140 is divided into an introduction chamber 140a and a brake hydraulic fluid chamber 4m by the first sliding portion 4t. The introduction chamber 140a is a substantially cylindrical space defined by the axial end surface of the first sliding portion 4t facing the second end plate 4g4 and the casing 4g, and is an inlet provided in the second end plate 4g4. It communicates with port 4j. The inlet port 4j is connected to the cooling oil pump 19 (see FIG. 2).

  The brake hydraulic oil chamber (positive chamber) 4m is a cylindrical space defined by the spring chamber side end surface of the first sliding portion 4t, the outer peripheral surface of the second sliding portion 4s, and the casing 4g. The hydraulic oil introduction port 4n provided in the second end plate 4g4 is communicated. The hydraulic oil introduction port 4n is connected to the pilot pump 9 via the brake control valve 6 and the brake switching valve 5 (see FIG. 2).

  The introduction chamber 140a and the brake hydraulic oil chamber 4m expand and contract in the axial direction as the piston portion 4e moves in the axial direction, and the volume of the internal space fluctuates (FIGS. 3A and 3B). reference). In addition, an O-ring is disposed between the through hole 145 and the second sliding portion 4s, and the brake hydraulic oil chamber 4m and the spring chamber 143 are isolated from each other. An O-ring is disposed between the sliding chamber 140 and the first sliding portion 4t, and isolates the brake hydraulic fluid chamber 4m from the introduction chamber 140a.

  Thus, a hydraulic cylinder device is constituted by the piston part 4e and the brake hydraulic oil chamber 4m, and a driving force can be applied to the piston part 4e by applying a pilot pressure to the brake hydraulic oil chamber 4m.

  When the brake hydraulic oil chamber 4m reaches the tank pressure, the pressing member 4p is moved toward the first end plate 4g3 by the urging force of the spring 4f, that is, in the direction close to the friction plate, and fixed to the rotating friction plate 4a. The friction plate 4b is pressed. As a result, the frictional force acts as a braking force on the surface of the rotating friction plate 4a (the surface of the friction material 148), and the rotation of the carrier shaft 4i is prevented.

  When the pilot pressure acts on the brake hydraulic oil chamber 4m as a brake release pressure, the pressing member 4p moves toward the second end plate 4g4 against the urging force of the spring 4f, that is, moves away from the friction plate. Thus, a gap is formed between the rotating friction plate 4a and the fixed friction plate 4b. Thereby, the pressure contact force between the rotating friction plate 4a and the fixed friction plate 4b is removed, and the rotating friction plate 4a and the carrier shaft 4i can be rotated.

  An operation in the automatic brake mode, which is a mode for performing power hoisting / lowering, and an operation in a neutral free mode, which is a mode for performing free fall, will be described. The mode switching between the neutral free mode and the automatic brake mode is performed based on the determination values of the operation pressure sensor 15, the brake circuit pressure sensor 16, and the brake mode switch 17. As shown in FIG. 2, in the automatic brake mode, the controller 18 switches the brake switching valve 5 to the position (D), and in the neutral free mode, the controller 18 switches the brake switching valve 5 to the position (C).

−Operation during power hoisting / lowering (automatic brake mode) −
When the winch operation lever 13 shown in FIG. 2 is operated to the winding position or the lowering position, the pilot pressure from the pilot pump 9 acts on the control valve 11 and the spool of the control valve 11 is driven. Thus, the pressure oil from the main pump 12 is supplied to the hydraulic motor 1. At the same time, the pilot pressure from the pilot pump 9 also acts on the motor brake switching valve 7 via the high pressure selection valve 14. Accordingly, the motor brake switching valve 7 is switched to the position (A), and the pilot pressure from the pilot pump 9 drives the motor brake cylinder 8 to the brake release side, so that the hydraulic motor 1 is driven to rotate.

  In the automatic brake mode, the brake switching valve 5 is switched to the position (D), and the pilot pressure from the pilot pump 9 that is the brake release pressure is shut off by the brake switching valve 5. Accordingly, the brake hydraulic oil chamber 4m becomes a tank pressure, and the rotating friction plate 4a and the fixed friction plate 4b are pressed against each other by the urging force of the spring 4f to apply the braking force to the planetary carrier 2d. 4 is fixed.

  In the automatic brake mode, when the sun gear 2a of the planetary reduction mechanism 2 is rotated by the rotational driving force of the hydraulic motor 1, the planetary gear 2b rotates and the winding drum 3 connected to the ring gear 2c and the ring gear 2c rotates. Winding or lowering by power is performed.

− Operation during free fall (neutral free mode) −
When the winch operation lever 13 is operated to the neutral position, the control valve 11 blocks the flow of pressure oil from the main pump 12 to the hydraulic motor 1. Since the pilot pressure oil is not supplied to the motor brake switching valve 7 via the high pressure selection valve 14, the motor brake switching valve 7 is switched to the position (B). Since the pilot pressure to the motor brake cylinder 8 is cut off by the motor brake switching valve 7, the motor brake is operated by the biasing force of the spring. In this state, when the braking force of the brake 4 is released, the take-up drum 3 freely rotates due to its own weight suspended from the hook 110.

  The brake 4 has a brake control valve 6 that reduces the pilot pressure from the pilot pump 9 according to the operation amount of the brake pedal 6a and outputs it as a brake release pressure, and adjusts the braking force by controlling the brake release pressure. It has a function that can. The operator can adjust the brake force (braking force) by the brake 4 and adjust the free fall speed by adjusting the brake release pressure to the brake 4 via the brake control valve 6 by operating the brake pedal 6a.

  In the hoisting winch 105, cooling oil (working oil) is forcibly circulated in order to cool the friction plate that generates heat during free fall braking. The cooling oil is supplied by a cooling oil pump 19 installed exclusively for the cooling oil.

  As described above, the casing 4g is provided with the inlet port 4j for introducing the cooling oil into the brake 4 and the outlet port 4k for discharging the cooling oil to the outside of the brake 4. As shown in FIG. 3, the inlet port 4j communicates with the carrier shaft chamber 141 via the introduction chamber 140a and the internal flow path of the piston portion 4e, and the outlet port 4k communicates with the spring chamber 143.

  The flow of the cooling oil will be described with reference to FIG. In FIG. 3, the flow of the cooling oil is schematically shown by arrows. The cooling oil introduced from the inlet port 4j into the introduction chamber 140a of the casing 4g is introduced into the carrier shaft chamber 141 through the internal flow path of the piston portion 4e. The cooling oil introduced into the carrier shaft chamber 141 flows into the disk chamber 142 from the inner peripheral side of the disk chamber 142, passes through the disk chamber 142, and flows into the outer peripheral flow path 144 on the outer peripheral side of the disk chamber 142. The cooling oil introduced into the outer peripheral flow path 144 flows into the spring chamber 143, is discharged out of the casing 4g from the outlet port 4k, and is returned to the tank 10.

  As the cooling oil passes between the plurality of friction plates arranged in the disk chamber 142, the heat generated in the friction plates is absorbed by the cooling oil, and the friction plates are cooled. As described above, since the groove 149 is provided in the friction material 148 of the rotating friction plate 4a, the cooling oil is not affected even when the friction plates are in pressure contact with each other (see FIG. 3B). Then, it flows from the carrier shaft chamber 141 to the outer peripheral flow path 144 through the groove 149.

  The design pressure of the casing 4g is generally determined to be lower than the allowable pressure of the oil seal 4h. In the present embodiment, as shown in FIG. 2, a cooling circuit safety valve 20 is provided on the discharge side of the cooling oil pump 19 so that the internal pressure of the casing 4g is equal to or lower than the allowable pressure of the oil seal 4h. The cooling circuit safety valve 20 is a relief valve that discharges the cooling oil to the tank 10 when the discharge pressure of the cooling oil pump 19 reaches a set pressure, and regulates the maximum pressure of the hydraulic circuit.

With reference to FIG. 3 and FIG. 5, of the force acting on the pressing member 4 p, the force other than the driving force by the press contact force adjusting device including the spring 4 f and the hydraulic cylinder device (4 e, 4 m) will be described. To do. In the following description, as shown in FIG. 3, the pressure on the inlet side of the cooling oil with respect to the brake 4, that is, the pressure of the cooling oil on the inner peripheral side of the disk chamber 142 is referred to as inlet pressure P _2. outlet pressure of the oil, i.e. the pressure of the cooling oil in the outer peripheral side of the disc chamber 142 referred to as the outlet pressure P _1. In the present embodiment, the cooling oil flows from the inner peripheral side to the outer peripheral side of the disk chamber 142, and pressure loss due to passage resistance occurs in the disk chamber 142. The pressure P ₂ becomes higher than the outlet pressure P ₁ on the outer peripheral side of the disk chamber 142 (P ₂ > P ₁ ).

ここで、Ｄ_１は押し当て面４ｒ１の外径、Ｄ_４は第２摺動部４ｓの外径（すなわち、貫通孔１４５の径）、Ｐ_１は出口圧力（すなわち、バネ室１４３の圧力）である。π／４×（Ｄ_１ ^２−Ｄ_４ ^２）は、図中、Ｄ_１とＤ_４との間の円環状の受圧面の面積Ａ_１４を表している。 (1-1) a force _{F 1} acting on the push member 4p by the outlet pressure _{P 1}
A force F ₁ acting on the pressing member 4p by the outlet pressure P ₁ is a direction in which the pressing member 4p is brought close to the friction plate (right direction in the drawing), that is, a direction in which the pressure contact force between the friction plates is increased (hereinafter, a braking force increasing direction). ) And is expressed by equation (1).

Here, the outer diameter of the contact surface 4R1 _{D 1} is pushed, _{D 4} is the outer diameter of the second sliding portion 4s (i.e., the diameter of the through hole 145), _{P 1} is the outlet pressure (i.e., pressure in the spring chamber 143) It is. π / 4 × (D ₁ ² −D ₄ ² ) represents an area A ₁₄ of an annular pressure receiving surface between D ₁ and D ₄ in the drawing.

ここで、Ｄ_２は押し当て面４ｒ１の内径、Ｄ_３は第１摺動部４ｔの外径（すなわち、摺動室１４０の径）、Ｐ_２は入口圧力（すなわち、キャリア軸室１４１、ピストン部４ｅの内部流路および導入室１４０ａの圧力）である。π／４×（Ｄ_２ ^２−Ｄ_３ ^２）は、図中、Ｄ_２とＤ_３との間の円環状の受圧面の面積Ａ_２３を表している。 (1-2) a force _{F 2} acting on the push member 4p by the inlet pressure _{P 2}
Force F ₂ acting on the push member 4p by the inlet pressure P _2, the direction (leftward direction) to separate the pressing member 4p from the friction plate, that is, the direction to reduce the pressure contact force of the friction plates are (hereinafter, the braking force decreasing direction It is a force acting on this and is expressed by equation (2).

Here, the inner diameter of the contact surface 4R1 _{D 2} is pushed, _{D 3} is the outer diameter of the first sliding portion 4t (i.e., the diameter of the slide chamber 140), _{P 2} is the inlet pressure (i.e., the carrier shaft chamber 141, a piston Pressure of the internal flow path of the portion 4e and the introduction chamber 140a). π / 4 × (D ₂ ² −D ₃ ² ) represents an area A ₂₃ of an annular pressure receiving surface between D ₂ and D ₃ in the drawing.

ここで、π／４×（Ｄ_１ ^２−Ｄ_２ ^２）は、図中、Ｄ_１とＤ_２との間の円環状の受圧面の面積、すなわち押し当て面４ｒ１の面積Ａ_１２を表している。 (1-3) Force F ₃ acting on the pressing member 4p by the distributed pressure P ₃ between the friction plates
Figure 5 is a schematic diagram schematically showing the distribution pressure P ₃ generated when the cooling oil to pass through the friction plates. As shown in FIG. 5, the friction plates by the cooling oil to pass through, the distribution pressure P ₃ occurs, the force F ₃ which the braking force decreasing direction pushes the push member 4p is generated. Assuming that the distribution pressure P ₃ is a distribution pressure that linearly changes from the inlet pressure P ₂ to the outlet pressure P ₁ , the force F ₃ acting on the pressing member 4 p due to the distribution pressure P ₃ between the friction plates is expressed by Equation (3). It is represented by

Here, π / 4 × (D ₁ ² −D ₂ ² ) represents the area of the annular pressure receiving surface between D ₁ and D _{2 in the} drawing, that is, the area A ₁₂ of the pressing surface 4r1. Yes.

式（４）の条件を考慮すると、圧力バランスによっては、ブレーキ力増加方向の力と、ブレーキ力減少方向の力とが等しくなる相殺条件が存在する。この相殺条件は、式（５）で表される。

In this embodiment, the pressing member 4p, the area A ₁₄ of the pressure receiving surface of the outlet pressure P ₁ is applied is the area A ₂₃ of the pressure receiving surface of the inlet pressure P ₂ is applied is distributed pressure P ₃ of the pressure receiving surface which acts to be larger than the sum of the area _{a 12,} which is determined the shape of the pressing member 4p, the magnitude relation of _{D 1, D 2, D 3} , D 4 described above, the formula (4) .

Considering the condition of equation (4), depending on the pressure balance, there is an offset condition in which the force in the direction of increasing brake force is equal to the force in the direction of decreasing brake force. This cancellation condition is expressed by equation (5).

Substituting Equations (1) to (3) into Equation (5) yields Equation (6).

Differential pressure ΔP between the inlet pressure _{P 2} and the outlet pressure _{P 1} is expressed by the formula (7a). Incidentally, when the inlet pressure _{P 2} represents the outlet pressure _{P 1} and the differential pressure ΔP becomes as shown in Equation (7b).

Substituting equation (7b) into equation (6) and rearranging results in equation (8).

In this embodiment, to detect the differential pressure [Delta] P, by adjusting the outlet pressure P ₁ as equation (8) is satisfied, the force acting on the push member 4p caused by the internal pressure of the casing 4g It is reduced and the brake operability is improved.

As shown in FIG. 2, in this embodiment, in order to adjust the outlet pressure P _1, in an oil passage between the outlet port 4k and the tank 10 is provided with the electromagnetic relief valve 21. In order to detect the differential pressure ΔP, a cooling circuit inlet pressure sensor 22i is provided in the oil passage between the cooling oil pump 19 and the inlet port 4j, and the cooling circuit is provided between the electromagnetic proportional relief valve 21 and the outlet port 4k. An outlet pressure sensor 22o is provided.

The controller 18 is configured to include an arithmetic processing unit having a CPU, a storage device such as a ROM and a RAM, and other peripheral circuits. In the storage device of the controller 18, dimension data (D ₁ , D ₂ , D ₃ , D ₄ ) of each component member of the brake 4 and information of the formula (8) are stored in advance.

The controller 18, the cooling circuit inlet pressure sensor 22i and the cooling circuit outlet pressure sensor 22o is connected, a signal representing the cooling circuit inlet pressure sensor 22i inlet pressure P ₂ detected by and detected by the cooling circuit outlet pressure sensor 22o signal representative of the output pressure P ₁ that is is input (entrance pressure detecting process). The controller 18 calculates the differential pressure ΔP from the inlet pressure _{P 2} and the outlet pressure _{P 1} Tokyo (differential pressure calculation process).

The controller 18 calculates the target outlet pressure P ₁ based on the calculated differential pressure ΔP, the dimensions D ₁ , D ₂ , D ₃ , D ₄ stored in the storage device, and the equation (8). (Target outlet pressure calculation processing). Controller 18, the actual outlet pressure to control the value of the current flowing to the electromagnetic proportional relief valve 21 solenoid such that the outlet pressure P ₁ to the target (current value control process). The controller 18 repeatedly executes the above-described inlet / outlet pressure detection processing, differential pressure calculation processing, target outlet pressure calculation processing, and current value control processing at a predetermined control cycle.

According to the first embodiment described above, the following operational effects are obtained.
(1) Force other than the driving force by the pressure contact force adjusting device (spring 4f and hydraulic cylinder device (4e, 4m)) and acting on the pressing member 4p so as to increase the pressure contact force between the friction plates. The outlet of the cooling oil to the brake 4 so that Fi (= F ₁ ) and the force Fd (= F ₂ + F ₃ ) acting on the pressing member 4p so as to reduce the pressure contact force between the friction plates are balanced. The force acting on the pressing member 4p was controlled by adjusting the pressure on the side (exit pressure P ₁ ). Thereby, regardless of the flow rate of the cooling oil and the temperature of the cooling oil, the force Fi and the force Fd can be balanced, and the influence of the pressure of the cooling oil in the casing 4g on the brake operability can be reduced.

  In the technique described in Patent Document 1 (hereinafter referred to as the conventional technique), when the engine speed increases and the relief valve provided on the discharge side of the cooling oil pump exceeds the relief set pressure, the discharge oil of the cooling oil pump A part is bypassed via a relief valve. Therefore, in a state before the relief valve is operated, there is a problem that the influence of the pressure of the cooling oil in the casing on the brake operability cannot be reduced. Further, the prior art does not consider that the pressure loss changes as the viscosity of the cooling oil changes according to the temperature.

  On the other hand, according to the present embodiment, the brake operation is performed regardless of the change in the flow rate of the cooling oil (that is, even when the flow rate of the cooling oil is low), and regardless of the change in the temperature of the cooling oil. It is possible to prevent the sex from changing.

(2) In the prior art, the cooling oil is actively bypassed to reduce the pressure loss, so the amount of cooling oil introduced into the brake is reduced by the amount of the bypassed cooling oil. Cooling performance may be reduced. In contrast, in the present embodiment, since it is configured to adjust the outlet pressure P _1, it is possible to prevent the cooling performance decreases.

(3) Since the force in the brake force decreasing direction acting on the pressing member 4p can be nullified by the pressure of the cooling oil in the casing 4g, safety is improved.
(4) Since it is not necessary to set the urging force of the spring 4f in consideration of the braking force decreasing direction force acting on the pressing member 4p due to the pressure of the cooling oil in the casing 4g, the spring 4f is reduced in size and weight. Thus, the brake 4 can be reduced in size and weight.

-Second Embodiment-
A brake device 2B according to the second embodiment will be described with reference to FIG. 6 and FIG. In the figure, the same reference numerals are assigned to the same or corresponding parts as those in the first embodiment, and the differences will be mainly described. FIG. 6 is a hydraulic circuit diagram showing the configuration of the winch device having the brake device 2B according to the second embodiment, and FIG. 7 is a diagram showing the configuration of the brake according to the second embodiment. In the first embodiment, and the electromagnetic proportional relief valve 21 is provided as a means for adjusting the outlet pressure P _1, example was described of adjusting the outlet pressure P ₁ so cancel condition is satisfied (see FIG. 2). On the other hand, in 2nd Embodiment, it replaces with the electromagnetic proportional relief valve 21, and assist force is provided to the direction which increases the press-contact force of friction plates with respect to the press member 4p, ie, a braking force increase direction. An assist hydraulic cylinder device is provided as an assist force generator.

In the first embodiment, the pressing member 4p, receiving the area A ₁₄ of the pressure receiving surface of the outlet pressure P ₁ is applied is the area A ₂₃ of the pressure receiving surface of the inlet pressure P ₂ is applied is distributed pressure P ₃ acting as it is larger than the sum of the area a ₁₂ of the surface, the shape of the pressing member 4p has been determined, by adjusting the outlet pressure P _1, it was possible to establish the nulling condition.

In contrast, in the second embodiment, the area of the pressure receiving surface of the outlet pressure P ₁ is applied is the area of the pressure receiving surface of the inlet pressure P ₂ in area and distribution pressure P ₃ of the pressure receiving surface which acts acts The shape of the pressing member 4p is determined so that the sum of the values becomes equal.

Therefore, by adjusting the outlet pressure P _1, it is impossible to establish the nulling condition by pressure balance, the braking force decreasing direction of the force generated by the internal pressure of the casing 4g becomes larger state than the force of the braking force increasing direction .

  Therefore, in the second embodiment, the force acting to decrease the pressure contact force between the friction plates against the pressing member 4p by the pressure of the cooling oil and the friction plate against the pressing member 4p by the pressure of the cooling oil. A force corresponding to a difference from a force acting so as to increase the pressure contact force between each other is applied as an assist force by the assist force generator.

  As a result, the force acting on the pressing member 4p so as to increase the pressure contact force between the friction plates, and the force other than the driving force by the pressure contact force adjusting device, and the pressure contact force between the friction plates are reduced. The force acting on the pressing member 4p can be balanced regardless of the flow rate and temperature of the cooling oil.

  This will be specifically described below. The assist hydraulic cylinder device includes an assist hydraulic oil chamber (positive chamber) 24u (see FIG. 7) provided in the brake 4 and a piston portion 4e. The assist force generated by the assist hydraulic cylinder device is obtained by adjusting the operation of the electromagnetic proportional pressure reducing valve 23 (see FIG. 6) for adjusting the pressure of the pressure oil supplied from the pilot pump 9 to the assist hydraulic oil chamber 24u. It is controlled by the controller 18 that controls it.

As shown in FIG. 7, the piston portion 4e has a third sliding portion 24w that protrudes from the first sliding portion 4t toward the inlet port 4j. The outer diameter of the third sliding portion 24w is the same dimension as the outer diameter D ₄ of the second sliding portion 4s. The second end plate 24g4 is provided with a cylindrical portion protruding from the inner surface, and the third sliding portion 24w is held inside the cylindrical portion so as to be slidable in the axial direction.

  The assist hydraulic oil chamber 24u is a cylindrical space defined by the outer peripheral surface of the third sliding portion 24w, the end surface on the inlet port side of the first sliding portion 4t, and the casing 4g, and is formed in the second end plate 24g4. It communicates with the provided assist port 24v. The assist port 24v is connected to the pilot pump 9 via an electromagnetic proportional pressure reducing valve 23 as shown in FIG.

  The electromagnetic proportional pressure reducing valve 23 is provided in an oil passage connecting the pilot pump 9 and the assist port 24v. The electromagnetic proportional pressure reducing valve 23 is connected to the controller 18 and reduces the discharge pressure of the pilot pump 9 according to a control signal from the controller 18 and outputs it to the assist port 24v.

With reference to FIG. 7, the force other than the driving force by the press contact force adjusting device including the spring 4f and the hydraulic cylinder device (4e, 4m) among the forces acting on the pressing member 4p will be described.
(2-1) a force _{F 1} acting on the push member 4p by the outlet pressure _{P 1}
The force F ₁ acting on the pressing member 4p due to the outlet pressure P ₁ is expressed by the expression (1) as in the first embodiment.

ここで、Ｄ_４は第３摺動部２４ｗの外径であり、π／４×（Ｄ_２ ^２−Ｄ_４ ^２）は、図中、Ｄ_２とＤ_４との間の円環状の受圧面の面積Ａ_２４を表している。 (2-2) a force _{F 2} acting on the push member 4p by the inlet pressure _{P 2}
The force F ₂ that acts on the pressing member 4p due to the inlet pressure P ₂ is a force that acts in the brake force decreasing direction, and is represented by Expression (9).

Here, D ₄ is the outer diameter of the third sliding portion 24w, and π / 4 × (D ₂ ² −D ₄ ² ) is an annular pressure receiving surface between D ₂ and D _{4 in the} figure. it represents the area _{a 24.}

(2-3) Force F ₃ acting on the pressing member 4p by the distributed pressure P ₃ between the friction plates
The force F ₃ acting on the pressing member 4p by the distributed pressure P ₃ between the friction plates is expressed by the expression (3) as in the first embodiment.

ここで、π／４×（Ｄ_３ ^２−Ｄ_４ ^２）は、図中、Ｄ_３とＤ_４との間の円環状の受圧面の面積Ａ_３４を表している。 (2-4) Assist force F _A
Be to act as an assist pressure a pilot pressure from the pilot pump 9 to the assist hydraulic oil chamber 24u, it is possible to generate an assist force F _A to increase the pressure contact force of the friction plates are relative to the pressing member 4p. Assist force _{F A,} when the assist pressure and _{P A,} represented by the formula (10).

Here, π / 4 × (D ₃ ² −D ₄ ² ) represents the area A ₃₄ of the annular pressure receiving surface between D ₃ and D _{4 in} the figure.

A balance formula between the force in the increasing direction of the brake force acting on the pressing member 4p and the force in the decreasing direction of the brake force, which is a force other than the driving force by the pressure contact force adjusting device, is expressed by Formula (11).

When Expression (1), Expression (9), and Expression (3) are substituted into Expression (11), Expression (12) is obtained.

When formula (12) is modified and formula (7b) is substituted and arranged, formula (13) is obtained.

Substituting equation (10) into equation (13) and rearranging results in equation (14).

In the storage device of the controller 18, the information of the formula (14) is stored in advance. In the second embodiment, detects a differential pressure [Delta] P, by adjusting the assist pressure P _A as equation (14) holds, a force other than the driving force by the pressing force adjusting device, the friction plate The force acting on the pressing member 4p so as to increase the pressure contact force between them and the force acting on the pressing member 4p so as to decrease the pressure contact force between the friction plates are balanced.

The controller 18, the cooling circuit inlet pressure sensor 22i and the cooling circuit outlet pressure sensor 22o is connected, a signal representing the cooling circuit inlet pressure sensor 22i inlet pressure P ₂ detected by and detected by the cooling circuit outlet pressure sensor 22o signal representative of the output pressure P ₁ that is is input (entrance pressure detecting process). The controller 18 calculates the differential pressure ΔP from the cooling circuit inlet pressure has been the inlet pressure P ₂ detected by the sensor 22i cooling circuit outlet pressure sensor 22o exit pressure P ₁ Metropolitan detected in (differential pressure calculation process).

Controller 18, operations and the calculated differential pressure [Delta] P, the dimensions _{D 1, D 2, D 3} , D 4 which is stored in the storage device, based on the equation (14), the assist pressure _{P A} to the target (Target assist pressure calculation processing). The controller 18 controls the value of the current flowing to the solenoid of the solenoid proportional pressure reducing valve 23 as an assist pressure P _A is applied to the assist hydraulic oil chamber 24u (current value control process). The controller 18 repeatedly executes the above-described inlet / outlet pressure detection processing, differential pressure calculation processing, target assist pressure calculation processing, and current value control processing at a predetermined control cycle.

In the second embodiment, the pressing member 4p has a force other than the driving force by the pressure contact force adjusting device (spring 4f and hydraulic cylinder device (4e, 4m)) so as to increase the pressure contact force between the friction plates. The force Fi (= F ₁ + F _A ) acting against the force Fd (= F ₂ + F ₃ ) acting on the pressing member 4p so as to reduce the pressure contact force between the friction plates is balanced. by adjusting the assist pressure P _a, and to control the force acting on the pressing member 4p. According to such 2nd Embodiment, there exists an effect similar to (1)-(4) demonstrated in 1st Embodiment. Further, according to the second embodiment, it is not necessary to perform the control for increasing the outlet pressure P _1, it is possible to suppress lower than the internal pressure of the casing 4g in the first embodiment, the allowable An inexpensive oil seal 4h having a low pressure can be employed.

-Third embodiment-
A brake device according to a third embodiment will be described with reference to FIG. In the figure, the same reference numerals are assigned to the same or corresponding parts as those in the first embodiment, and the differences will be mainly described. FIG. 8 is a diagram illustrating a configuration of the brake 34 according to the third embodiment.
In the first embodiment, the embodiment in which the present invention is applied to the brake 4 having a configuration in which the cooling oil passes from the inner peripheral side of the disk chamber 142 toward the outer peripheral side has been described. In contrast, in the third embodiment, an embodiment in which the present invention is applied to a brake 34 having a configuration in which cooling oil passes from the outer peripheral side of the disk chamber 342 toward the inner peripheral side will be described.

In the configuration of the first embodiment, when the flow direction of the cooling oil to the contrary, the pressing member 4p, and the area of the pressure receiving surface area and distribution pressure P ₃ of the pressure receiving surface of the outlet pressure P ₁ is applied is applied sum of, for inlet pressure P ₂ is less than the area of the pressure receiving surface which acts, by adjusting the outlet pressure P _1, it is impossible to establish the nulling condition.

  In order to establish the canceling condition, as in the first embodiment, the area of the pressure receiving surface where the internal pressure acts in the direction of increasing brake force is larger than the area of the pressure receiving surface where the internal pressure acts in the direction of decreasing brake force. There is a need to. In the third embodiment, in the brake 34 in which the cooling oil flows from the outer peripheral side to the inner peripheral side of the disk chamber 342, the area of the pressure receiving surface on which the internal pressure acts in the braking force increasing direction is the internal pressure in the braking force decreasing direction. The shape of the pressing member 34p is determined so as to be larger than the area of the pressure receiving surface on which the pressure acts.

  The brake 34 according to the third embodiment includes a carrier shaft 4i, a rotating friction plate 4a, and a fixed friction plate 4b having the same configuration as that of the first embodiment. The brake 34 according to the third embodiment is different from the first embodiment in the configuration of the pressing member 34p and the positions of the inlet port 34j and the outlet port 34k.

The pressing member 34p includes an annular pressure plate 34d and a piston portion 34e extending in the axial direction from the outer peripheral portion of the pressure plate 34d. The pressure plate 34d has a pressing surface 34r1 that comes into contact with the fixed friction plate 4b. Pressing surface 34r1 is an annular plane, an inside diameter D ₂ is substantially the same size as the inner diameter of the friction member 148 of the rotating friction plate 4a, the outer friction material 148 of the outer diameter D ₁ is rotational friction plates 4a The dimensions are almost the same as the diameter (D ₁ > D ₂ ). A spring 4f is disposed between the surface opposite to the pressing surface 34r1 and the second end plate 34g4 of the casing 4g. The spring 4f is an elastic member that urges the pressing member 34p toward the friction plate by an elastic force.

The piston part 34e is formed in a cylindrical shape and has an internal flow path through which cooling oil passes. The piston portion 34e is provided with a pressure plate 34d at one axial end, a first sliding portion 34t at the other axial end, and a second sliding portion 34s at the axial center. Outer diameter _{D 3} of the first sliding portion 34t is larger than the outer diameter _{D 4} of the second sliding portion _{34s (D 3> D 4)} .

  In the accommodation space of the casing 34g, a sliding chamber 340 in which the first sliding portion 34t is disposed, a spring chamber 343 in which the spring 4f is accommodated, and a carrier shaft chamber 341 in which an end portion of the carrier shaft 4i is accommodated. A disk chamber 342 in which the friction plate is accommodated, and an outer peripheral flow path 344 disposed on the outer peripheral side of the disk chamber 342 are formed.

  The sliding chamber 340 and the spring chamber 343, and the spring chamber 343 and the carrier shaft chamber 341 are communicated with each other. The carrier shaft chamber 341 and the outer peripheral flow path 344 communicate with each other via the disk chamber 342. The cooling oil outlet port 34k is provided in the second end plate 34g4, and the spring chamber 343 communicates with the outlet port 34k. The cooling oil inlet port 34j is provided on the outer peripheral wall of the second cylindrical portion 34g2, and the outer peripheral flow path 344 communicates with the inlet port 34j.

  The second cylindrical portion 34g2 of the casing 34g has a second sliding portion 362 having a sliding surface on which the second sliding portion 34s slides, and a sliding surface on which the first sliding portion 34t slides. A first sliding portion 361 is provided. A brake hydraulic oil chamber 34m is defined by the second sliding portion 362, the first sliding portion 361, the second sliding portion 34s, and the first sliding portion 34t.

  In the third embodiment, as in the first embodiment, when the brake hydraulic oil chamber 34m reaches the tank pressure, the pressing member 34p moves to the first end plate 4g3 side by the biasing force of the spring 4f. That is, it moves in the direction close to the friction plate and presses the rotating friction plate 4a and the fixed friction plate 4b. As a result, the frictional force acts as a braking force on the surface of the rotating friction plate 4a (the surface of the friction material 148), and the rotation of the carrier shaft 4i is prevented.

  When the pilot pressure acts on the brake hydraulic oil chamber 34m as a brake release pressure, the pressing member 34p moves to the second end plate 34g4 side against the biasing force of the spring 4f, and the rotating friction plate 4a and the fixed friction plate 4b. A gap is formed between the two. Thereby, the pressure contact force between the rotating friction plate 4a and the fixed friction plate 4b is removed, and the rotating friction plate 4a and the carrier shaft 4i can be rotated.

ここで、π／４×（Ｄ_３ ^２−Ｄ_２ ^２）は、図中、Ｄ_３とＤ_２との間の円環状の受圧面の面積Ａ_３２を表している。 The force acting on the pressing member 34p will be described.
(3-1) a force _{F 1} acting on the pressing member 34p by the outlet pressure _{P 1}
A force F ₁ that acts on the pressing member 34p due to the outlet pressure P ₁ is a force that acts in the direction of increasing braking force, and is represented by Expression (15).

Here, π / 4 × (D ₃ ² −D ₂ ² ) represents the area A ₃₂ of the annular pressure receiving surface between D ₃ and D _{2 in} the figure.

ここで、π／４×（Ｄ_４ ^２−Ｄ_１ ^２）は、図中、Ｄ_４とＤ_１との間の円環状の受圧面の面積Ａ_４１を表している。 (3-2) a force _{F 2} acting on the pressing member 34p by the inlet pressure _{P 2}
The force F ₂ acting on the pressing member 34p due to the inlet pressure P ₂ is a force acting in the braking force decreasing direction, and is represented by Expression (16).

Here, π / 4 × (D ₄ ² −D ₁ ² ) represents the area A ₄₁ of the annular pressure receiving surface between D ₄ and D _{1 in} the figure.

(3-3) Force F ₃ acting on the pressing member 34p by the distributed pressure P ₃ between the friction plates
The force F ₃ acting on the pressing member 34p by the distributed pressure P ₃ between the friction plates is expressed by the expression (3) as in the first embodiment.

式（１７）を考慮すると、圧力バランスによっては、ブレーキ力増加方向の力と、ブレーキ力減少方向の力とが等しくなる相殺条件が存在する。この相殺条件は、第１の実施の形態と同様、式（５）で表される。 In the third embodiment, the pressing member 34p, the area _{A 32} of the pressure receiving surface of the outlet pressure _{P 1} is applied is the area _{A 41} of the pressure receiving surface of the inlet pressure _{P 2} is applied is distributed pressure _{P 3} acting Table to be larger than the sum of the area _{a 12} of the pressure receiving surface are determined shape of the pressing member 34p _is, the magnitude relation of _{D 1, D 2, D 3} , D 4 is the formula (17) to Is done.

Considering the equation (17), depending on the pressure balance, there is a canceling condition in which the force in the braking force increasing direction is equal to the force in the braking force decreasing direction. This canceling condition is expressed by Expression (5), as in the first embodiment.

Substituting Equation (3), Equation (15), and Equation (16) into Equation (5) yields Equation (18).

Substituting equation (7b) into equation (18) and rearranging results in equation (19).

As in the first embodiment, the third embodiment includes an electromagnetic proportional relief valve 21, a cooling circuit inlet pressure sensor 22i, and a cooling circuit outlet pressure sensor 22o (see FIG. 2). In the third embodiment, detects a differential pressure [Delta] P, and by adjusting the outlet pressure P ₁ as equation (19) holds, the action of the pressing member 34p caused by the internal pressure of the casing 34g The force is reduced and the brake operability is improved.

  According to such 3rd Embodiment, there exists an effect similar to 1st Embodiment.

  Thus, this invention produces the effect that a brake operativity can be improved irrespective of the change of the flow volume and temperature of a cooling oil by determining the shape of a press member according to the flow direction of a cooling oil.

-About the method of judging the validity of the cancellation condition-
Here, in the configuration of the brake according to the first embodiment and the third embodiment, by adjusting the outlet pressure P _1, an example of a method of determining whether it is possible to satisfy the offset condition description To do. By adjusting the outlet pressure P _1, whether it is possible to satisfy the cancellation condition, determine the offset condition representing an exit pressure P ₁ in the differential pressure [Delta] P, whether the coefficient of the differential pressure [Delta] P is positive do it. When the coefficient of the differential pressure ΔP is positive, the canceling condition can be established by adjusting the outlet pressure P _{1. When} the coefficient of the differential pressure ΔP is 0 or negative, the canceling condition is canceled by adjusting the outlet pressure P _1. The condition cannot be satisfied.

(Determination method when the flow of cooling oil is reversed in the first embodiment)
In the first embodiment, when the inner peripheral side flow direction of the cooling oil from the outer peripheral side, a pressure receiving surface which acts inlet pressure P _2, the inverse relationship between the pressure receiving surface of the outlet pressure P ₁ is applied Become. Therefore, by replacing the _{P 1} and _{P 2} of the formula (6), equation (20) is obtained which represents the offset condition.

ここで、式（４）の大小関係があるため、式（２１）の差圧ΔＰの係数は式（２２）で表すように負となる。 Substituting equation (7b) into equation (20) and rearranging results in equation (21).

Here, since there is a magnitude relationship of the equation (4), the coefficient of the differential pressure ΔP of the equation (21) is negative as represented by the equation (22).

差圧ΔＰの係数が負になるため、出口圧力Ｐ_１を調整することで相殺条件を成立させることはできない。第１の実施の形態に係るブレーキ４において、摩擦板の外周側から内周側に向かって冷却油を流す場合には、常にブレーキ力増加方向の力が押圧部材４ｐに作用することになる。

Since the coefficients of the differential pressure ΔP is negative, it is impossible to establish the nulling condition by adjusting the outlet pressure P _1. In the brake 4 according to the first embodiment, when cooling oil is allowed to flow from the outer peripheral side of the friction plate toward the inner peripheral side, a force in the brake force increasing direction always acts on the pressing member 4p.

(Determination method when the flow of cooling oil is reversed in the third embodiment)
In the third embodiment, when the outer peripheral side of the flow direction in the cooling oil from the inner circumferential side, a pressure receiving surface which acts inlet pressure P _2, the inverse relationship between the pressure receiving surface of the outlet pressure P ₁ is applied Become. Therefore, by replacing the _{P 1} and _{P 2} of the formula (18), equation (23) is obtained which represents the offset condition.

ここで、式（１７）の大小関係があるため、式（２４）の差圧ΔＰの係数は式（２５）で表すように負となる。 Substituting equation (7b) into equation (23) and rearranging results in equation (24).

Here, since there is a magnitude relationship of the equation (17), the coefficient of the differential pressure ΔP of the equation (24) is negative as represented by the equation (25).

差圧ΔＰの係数が負になるため、出口圧力Ｐ_１を調整することで相殺条件を成立させることはできない。第３の実施の形態に係るブレーキ３４において、摩擦板の内周側から外周側に向かって冷却油を流す場合には、常にブレーキ力増加方向の力が押圧部材３４ｐに作用することになる。

Since the coefficients of the differential pressure ΔP is negative, it is impossible to establish the nulling condition by adjusting the outlet pressure P _1. In the brake 34 according to the third embodiment, when cooling oil is allowed to flow from the inner peripheral side to the outer peripheral side of the friction plate, a force in the braking force increasing direction always acts on the pressing member 34p.

If nulling condition by adjusting the outlet pressure P ₁ that is satisfactory is determined, with the arrangement to adjust the outlet pressure P ₁ (first embodiment and the third embodiment) or assist force generating device By adopting the configuration (second embodiment), it is possible to improve the brake operability. If nulling condition by adjusting the outlet pressure P ₁ that can not be met is determined, by employing a configuration including an assist force generating device (second embodiment), it is possible to improve the braking properties it can.

The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.
(Modification 1)
In the above-described embodiment, mathematical expressions (expression (8), expression (14), expression (19)) representing the cancellation condition are stored in the storage device of the controller 18, and the cancellation condition expression and the inlet / outlet pressure (P _1, computing _{P 2)} and the differential pressure ΔP computed from the dimensions _{D 1, D 2, D 3} , D 4 Metropolitan stored in the storage device, the outlet pressure _{P 1} and the assist pressure _{P a} to the target However, the present invention is not limited to this. Advance, relationships and the differential pressure ΔP and the outlet pressure P _1, may be stored in a storage device the characteristics representing the relationship between the differential pressure ΔP and the assist pressure P _A in the look-up table format, the detected differential pressure ΔP it may read the exit pressure P ₁ or the assist pressure P _a, depending from the table.

(Modification 2)
In the above-described embodiment, an example in which the present invention is applied to a brake device for a winch of a crawler crane has been described. However, the present invention can also be applied to a mobile crane such as a telescopic crane or a fixed crane. .

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

4 brake (wet multi-plate brake), 4a rotating friction plate (friction plate), 4b fixed friction plate (friction plate), 4e piston part (hydraulic cylinder device), 4f spring (elastic member), 4g casing, 4m brake hydraulic oil Chamber (hydraulic cylinder device), 4p pressing member, 9 pilot pump (assist force generating device), 18 controller (acting force control device), 21 electromagnetic proportional relief valve (pressure adjusting device), 22i cooling circuit inlet pressure sensor (differential pressure) Detecting device), 22o cooling circuit outlet pressure sensor (differential pressure detecting device), 23 electromagnetic proportional pressure reducing valve (assist force generating device), 24u assist hydraulic oil chamber (assist force generating device), 34e piston part (hydraulic cylinder device), 34g casing, 34p pressing member, 105 hoist winch, B, 2B brake device

Claims (7)

A winch brake device comprising a wet multi-plate brake having an inlet through which cooling oil passing between a plurality of friction plates is introduced and an outlet through which the cooling oil is discharged,
The wet multi-plate brake is a pressing member that presses the friction plates together to generate a braking force;
A pressing force adjusting device that adjusts the pressing force between the friction plates by applying a driving force to the pressing member;
A force other than the driving force that acts on the pressing member, and an acting force that controls the force acting on the pressing member so that the force that increases the pressure contact force between the friction plates and the force that decreases the force are balanced. A winch brake device comprising a control device. The winch braking device according to claim 1,
The action force control device is a winch brake device configured to include a pressure adjusting device that adjusts the pressure on the outlet side of the cooling oil to the brake. The winch braking device according to claim 2,
The pressing member includes a first pressure receiving surface and a second pressure receiving surface,
In the brake, the internal pressure of the casing of the brake is applied to the first pressure receiving surface, thereby increasing the pressure contact force between the friction plates, and the internal pressure of the casing of the brake is applied to the second pressure receiving surface, It is configured to reduce the pressure contact between the friction plates,
The winch brake device in which the shape of the pressing member is determined so that the area of the first pressure receiving surface is larger than the area of the second pressure receiving surface. The winch brake device according to any one of claims 1 to 3,
The acting force control device is a winch brake device including an assist force generating device that applies an assist force for increasing a pressure contact force between the friction plates to the pressing member. The brake device for a winch according to claim 4,
The assist force generator is configured to generate a force corresponding to a difference between a force acting so as to decrease the pressure contact force between the friction plates against the pressing member and a force acting so as to increase the pressure member. A winch brake device that provides assist power. The winch brake device according to any one of claims 1 to 5,
A differential pressure detecting device for detecting a differential pressure between the pressure on the inlet side and the pressure on the outlet side of the cooling oil with respect to the brake;
The acting force control device is a winch brake device that operates in accordance with the differential pressure detected by the differential pressure detection device. The winch brake device according to any one of claims 1 to 6,
The pressing force adjusting device includes a resilient member that applies a driving force to the pressing member so as to increase the pressing force between the friction plates, and a driving force applied to the pressing member so as to reduce the pressing force between the friction plates. A winch brake device configured to include a hydraulic cylinder device that operates.

Images