Crushing device

Abstract

To provide a crusher capable of surely continuously maintaining a state of properly crushing a crushing object by securing a crushable state by temporarily changing an interval of an immobile tooth and a mobile tooth by controlling an adjustment part in response to a load to the mobile tooth.SOLUTION: Even if a load to a mobile tooth 11 increases by a crushable crushing object or an uncrushable foreign matter entering between an immobile tooth 11 and a mobile tooth 12, a further load increase is restrained by expanding an interval of the immobile tooth and the mobile tooth by displacing a swing jaw by an adjustment part controlled by a control part, and crushing of the crushing object or discharge of the foreign matter is performed, and after completing such the crushing or the discharge, the adjustment part is restored to an original state, and since the crushing is made continuable, in the case of the crushable crushing object, the mobile tooth 12 is quickly restored to the original sate by the adjustment part without inviting stopping of a device by a load increase, and a crushing piece can be maintained without the problem in a desired size, and crushing work is efficiently and accurately performed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a crushing device such as a jaw crusher that crushes objects to be crushed, such as stones. [Background technology]

[0002] Jaw crushers have been used as crushing devices for crushing stones, concrete waste, asphalt waste, etc. into desired sizes. Jaw crushers move movable teeth attached to a swing jaw relative to fixed stationary teeth, and crush an object to be crushed introduced between the movable teeth by clamping it between the movable teeth.

[0003] Among conventional jaw crushers, the single toggle type jaw crusher which is widely used usually has a rotating shaft which is driven by an electric motor, hydraulic motor or the like rotatably supported on the main body frame of the jaw crusher which fixedly supports the stationary teeth, and an eccentric shaft section which is integrally provided on this rotating shaft with its axis shifted, and the upper part of the swing jaw is attached and supported so as to be capable of rotating relative to the eccentric shaft section.

[0004] The lower part of the swing jaw abuts against one end of a toggle plate that is separately provided on the main frame and can swing, and the swing jaw is capable of swinging relative to the toggle plate while the toggle plate and swing jaw maintain their abutment and do not move apart. This allows the eccentric shaft, swing jaw, toggle plate, and main frame to form a link mechanism with the main frame as the stationary joint, the eccentric shaft as the driving joint, and the swing jaw as the driven joint, and allows for repeated generation of a specified movement, including swinging of the swing jaw to move it closer to and away from the stationary teeth.

[0005] The other end of the toggle plate, which abuts against the lower part of the swing jaw, opposite to the end abutting against the swing jaw, is positioned by a receiving member such as a toggle block provided on the main body frame. By adjusting the position of this receiving member (toggle block) and changing the swing center position of the toggle plate on the main body frame, the relative position of the swing jaw with respect to the stationary teeth can be adjusted forward and backward, and the gap between the moving teeth and the stationary teeth attached to the swing jaw can be adjusted to match the particle size distribution of the crushed pieces to be obtained by crushing the object to be crushed. An example of such a conventional jaw crusher capable of adjusting the gap between the moving teeth and the stationary teeth is disclosed in Japanese Patent Application Laid-Open No. 2001-70810. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-70810 A Summary of the Invention [Problem to be solved by the invention]

[0007] Conventional jaw crushers have the configuration exemplified in the above-mentioned patent document, and when a foreign object such as metal is inserted between the fixed teeth and the moving teeth, they are unable to crush it and become overloaded. If crushing were to continue in this state, it would lead to malfunctions such as damage to the device, so a mechanism was introduced to detect when an overload state occurs and stop the device.

[0008] In such conventional jaw crushers, when the rotating shaft for moving the swing jaw is driven by an electric motor, the current flowing through the electric motor, which is the driving source, increases as the load increases, and so it is common to judge an overload state in which foreign objects such as metals cannot be crushed by the current value of the electric motor. However, since the overload state was judged by the current value of the electric motor, if the current threshold for stopping the electric motor in response to an overload was set low, there was a problem that, for example, when the object to be crushed, such as stones, which should be crushed, is hard and difficult to break, the current value of the electric motor increases with a peak-high load, exceeding the threshold, and the electric motor is erroneously judged as overloaded, stopping, and crushing is interrupted. Each time the electric motor is stopped, it is necessary to remove the remaining object to be crushed, which hinders the start of the electric motor, from between the stationary and moving teeth in order to start the electric motor again, which takes time to restore and reduces the efficiency of the crushing work.

[0009] On the other hand, if the object to be crushed is hard, and the threshold value is set high so that the threshold value corresponding to the overload is not exceeded even if the current value of the motor increases due to the load related to crushing, the timing of determining that the load is overloaded is delayed even when the load increases due to foreign objects that cannot be crushed, which causes a problem that it takes time to stop the device and malfunctions caused by operating the device for a while in an overloaded state, such as bending of the toggle plate and damage to the bearings, are likely to occur. Since the parts where malfunctions such as damage and breakage occur due to the delayed shutdown are often key parts of the device that take a long time to restore, this also leads to a significant decrease in the efficiency of the crushing work.

[0010] On the other hand, in the case of a device that drives a rotating shaft with a hydraulic motor, an increase in load appears as an increase in hydraulic pressure in a hydraulic circuit including the hydraulic motor, so a hydraulic control mechanism is adopted that detects an overload in response to an increase in hydraulic pressure due to an increase in load and stops the drive, realizing a mechanism that can quickly detect an overload and stop the crushing. In addition, hydraulic drive, by its nature, is unlikely to cause an abnormal increase in load as in the case of an electric motor, and has the advantage that it is easier to generate torque at start-up compared to an electric motor and can be started up quickly after being stopped. However, such a device driven by a hydraulic motor has a problem that the drive mechanism is complex and large-scale, which is costly as a device, and the running cost is also high because the hydraulic pump needs to be constantly operated to generate hydraulic pressure.

[0011] The present invention has been made to solve the above-mentioned problems, and aims to provide a crushing device that can control an adjustment unit in accordance with the load on the moving teeth to temporarily increase the gap between the fixed teeth and the moving teeth, and then, following the crushing of the object to be crushed and the discharge of foreign matter, has the adjustment unit return the gap between the fixed teeth and the moving teeth to their original state, thereby ensuring a state in which crushing is possible, and reliably maintaining a state in which the object to be crushed can be properly crushed. [Means for solving the problem]

[0012] The crushing device of the present invention is a jaw crusher that comprises fixed teeth fixed to a main body frame, movable teeth arranged opposite the fixed teeth, and a swing jaw attached to the main body frame so as to be at least swingable, and crushes an object to be crushed placed between the fixed teeth and the movable teeth by moving the movable teeth together with the swing jaw relative to the fixed teeth.The crushing device is also equipped with an adjustment unit that positions the movable range of the swing jaw relative to the main body frame to adjust the distance between the fixed teeth and the movable teeth, and a control unit that controls at least the adjustment unit in response to fluctuations in the load on the movable teeth during crushing, and when the load on the moving teeth increases due to a crushable object to be crushed or an uncrushable foreign object, the control unit causes at least the adjustment unit to widen the distance between the fixed teeth and the moving teeth, and returns the adjustment unit to its original state after the object to be crushed that caused the increase in load is crushed, or after the foreign object is discharged from between the fixed teeth and the moving teeth.

[0013] Thus, according to the present invention, even if the load increases during crushing with the movable teeth due to a crushable object or an uncrushable foreign object that has entered between the fixed and movable teeth, the adjustment unit controlled by the control unit displaces the swing jaw and widens the gap between the fixed and movable teeth, suppressing further increase in load while crushing the object to be crushed or discharging the foreign object, and after completion of the crushing or discharging, the adjustment unit is returned to its original state, allowing the crushing to continue. In the case of a crushable object to be crushed, the device does not stop due to an increase in load, and the adjustment unit quickly returns the movable teeth to their original state, allowing the crushed pieces to be maintained at the desired size without any problems, allowing the crushing operation to be performed efficiently and accurately. Also, even if the load increases due to an uncrushable foreign object and leads to an overload, the adjustment unit widens the gap between the fixed and movable teeth, and after the foreign object is discharged, the adjustment unit quickly returns the gap between the fixed and movable teeth to its original state, minimizing interruptions to crushing and reducing losses.

[0014] Furthermore, the crushing device of the present invention may, as necessary, be provided with an electric motor for moving the swing jaw and moving teeth, and a fluid pressure motor for moving the swing jaw separately from the electric motor, and when the load on the moving teeth increases due to an uncrushable foreign object, the control unit stops driving the electric motor before the adjustment unit widens the gap between the fixed teeth and the moving teeth, and drives the fluid pressure motor in forward and reverse rotation to move the swing jaw, thereby repeatedly changing the gap between the fixed teeth and the moving teeth, making it easier for the foreign object that caused the increase in load to be expelled from between the fixed teeth and the moving teeth.

[0015] Thus, according to the present invention, the swing jaw can be moved by the fluid pressure motor to change the position of the moving teeth, and when an increase in load occurs due to an uncrushable foreign object, the control unit rotates the fluid pressure motor forward and reverse, causing the moving teeth integrated with the swing jaw to oscillate and change the distance between the fixed teeth and the moving teeth. The movement of the moving teeth approaching or moving away from the fixed teeth based on the forward and reverse rotation drive of the fluid pressure motor changes the positional relationship between the foreign object and the moving teeth, releasing the foreign object from a state in which it is stuck between the fixed teeth and the moving teeth and preventing it from moving, and causing the foreign object to fall between the fixed teeth and the moving teeth or transition to a state in which it is pulled upward, making it possible to discharge the foreign object. It is not necessary to use the adjustment unit to move the swing jaw to a state in which the distance between the fixed teeth and the moving teeth is widened, and crushing can be resumed quickly after the foreign object is discharged. In addition, by repeatedly changing the spacing between the fixed teeth and the moving teeth by driving the fluid pressure motor without adjusting the spacing between the fixed teeth and the moving teeth using an adjustment unit, large uncrushed objects to be crushed that were between the fixed teeth and the moving teeth along with the foreign matter are either crushed into small pieces and discharged, or remain uncrushed between the fixed teeth and the moving teeth, preventing the large objects to be crushed from leaking out from between the fixed teeth and the moving teeth.

[0016] Furthermore, in the crushing device according to the present invention, as necessary, the adjustment unit may be a fluid pressure cylinder disposed at a predetermined location on the opposite side of the swing jaw from the side where the fixed teeth are located, and the swing jaw may be positioned by changing the distance between one end and the other end of the fluid pressure cylinder, making it possible to adjust the distance between the fixed teeth and the moving teeth, and when the load on the moving teeth increases, the control unit may reduce the distance between one end and the other end of the fluid pressure cylinder as the adjustment unit to move the swing jaw and widen the distance between the fixed teeth and the moving teeth, and after the object to be crushed that caused the increase in load has been crushed, or after foreign matter has been discharged from between the fixed teeth and the moving teeth, the fluid pressure cylinder may be returned to its original state.

[0017] Thus, according to the present invention, the fluid pressure cylinder constituting the adjustment unit is capable of changing the distance between one end and the other end to position the swing jaw together with the moving teeth, and when the load on the moving teeth increases, the control unit operates the fluid pressure cylinder to move the swing jaw away from the fixed teeth, widening the distance between the fixed teeth and the moving teeth, while when the crushing of the object to be crushed or the discharge of foreign matter is completed, the fluid pressure cylinder is returned to its original state to restore the distance between the fixed teeth and the moving teeth. Therefore, the fluid pressure cylinder serving as the adjustment unit is expanded and contracted to move the swing jaw in response to changes in load, and the distance between the fixed teeth and the moving teeth can be quickly changed to respond to the change in load, and in the case of an increase in load due to a crushable object to be crushed, the object to be crushed, which has become easier to crush, can be crushed while the swing jaw is being retracted by operating the fluid pressure cylinder, and the crushing operation can be continued without stopping the device, improving work efficiency. In addition, in the event of an increase in load due to uncrushable foreign objects, the swing jaws can be retracted by operating the fluid pressure cylinder, and the foreign objects can be expelled from the gap between the spread fixed teeth and movable teeth. This allows the crushing operation to be resumed with minimal interruption to the crushing process, thereby reducing time loss related to the crushing operation.

[0018] In addition, the crushing device according to the present invention may, as necessary, comprise: a fluid pressure control means for controlling the fluid while temporarily reducing the distance between one end and the other end of the fluid pressure cylinder when the load on the moving teeth increases and the force attempting to reduce the distance between one end and the other end of the fluid pressure cylinder through the swing jaw becomes stronger, thereby making it possible to suppress the load on the moving teeth; and an electric motor control means for detecting a current flowing through the electric motor, and for stopping the drive of the electric motor when the detected current value satisfies a predetermined condition set in advance corresponding to a situation in which an uncrushable foreign object has entered between the fixed teeth and the moving teeth, causing an overload on the moving teeth, but for continuing the drive of the electric motor when the detected current value does not satisfy the condition. When a transient increase in the load on the moving teeth occurs due to a crushable object to be crushed, the fluid pressure control means controls the fluid in the fluid pressure circuit leading to the fluid pressure cylinder to such an extent that the current value of the electric motor detected by the electric motor control means does not satisfy the condition.

[0019] Thus, according to the present invention, when an increase in the load on the moving teeth causes the fluid pressure cylinder constituting the adjustment unit to receive a force and the fluid pressure in the fluid pressure circuit connected to the fluid pressure cylinder increases, the fluid pressure control means of the control unit controls the fluid in the fluid pressure circuit to cause the fluid pressure cylinder to temporarily operate in the contracting direction, thereby optimizing the load on the moving teeth, while the motor control means of the control unit stops the drive of the motor based on the value of the current flowing through the motor in a situation where the moving teeth are overloaded due to foreign matter, and when the load increases due to a crushable object to be crushed, the fluid pressure control means adjusts the fluid pressure. By controlling the fluid accompanying the contraction of the cylinder to reduce the load on the moving teeth and preventing the motor control means from stopping the drive of the motor, in response to an increase in load due to crushable objects, the distance between one end of the fluid pressure cylinder is temporarily shortened to move the swing jaws backward, and while the distance between the fixed teeth and the moving teeth is widened, the objects that have become easy to crush are crushed and the normal crushing state can be restored.This means that the crushing operation can be continued without the motor stopping due to a false detection of overload and the resulting interruption of crushing, thereby improving work efficiency.

[0020] In addition, since the motor control means of the control unit can reliably determine an overload state caused by an uncrushable foreign object from the current value of the motor, in the event of an overload due to a foreign object, the motor can be stopped, ensuring an opportunity to remove the foreign object from between the fixed and moving teeth.This prevents the foreign object from being mistaken for an object to be crushed and being erroneously discharged from the crushing device and mixed in with the crushed pieces, thereby avoiding problems caused by foreign objects in processes after the crushing device.

[0021] In addition, as necessary, the crushing device of the present invention has a motor control means of the control unit that presets a predetermined current value as a second threshold value, which is the current value flowing through the motor when an increase in load on the moving teeth occurs and is smaller than the current value when the condition corresponding to an overload situation is satisfied, and the motor control means detects the current flowing through the motor, and if the detected current value does not satisfy the condition and exceeds the second threshold value, continues to drive the motor while stopping the feeder that supplies the material to be crushed to the crushing device.

[0022] Thus, according to the present invention, the motor control means of the control unit sets a second threshold value for the current flowing through the motor, which corresponds to a state of increased load that is smaller than the state in which the moving teeth are overloaded due to foreign matter, and if the detection value of the current flowing through the motor by the motor control means exceeds the second threshold value, even if it does not satisfy the condition corresponding to overload, the drive of the motor is not stopped, but the feeder for supplying the objects to be crushed is stopped to interrupt the supply of the objects to be crushed.As the load on the moving teeth increases and the progress of crushing of the objects to be crushed slows down, no more objects to be crushed are supplied between the fixed teeth and the moving teeth, and the crushing of the objects that are difficult to crush or the discharge of foreign matter that caused the increase in load can be concentrated, and the crushing or discharge can be carried out quickly without being affected by the objects to be crushed supplied later, allowing the increased load state to be resolved in a shorter time and the crushing operation to be continued or resumed. [Brief description of the drawings]

[0023] [Figure 1]1 is a schematic configuration explanatory diagram of a crushing device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic side view of the side where a fluid pressure motor and a flywheel are installed in the crushing device according to one embodiment of the present invention. [Diagram 3] FIG. 2 is an explanatory diagram of a control system in the crushing device according to one embodiment of the present invention. [Figure 4] FIG. 13 is an explanatory diagram of an adjustment state of the gap between the stationary teeth and the movable teeth by the fluid pressure control means in the crushing device according to one embodiment of the present invention. [Diagram 5] 6 is a graph showing the changes in the current value of the electric motor, the pressure received by the fluid pressure cylinder, and the amount of positional deviation of the toggle block when a foreign object enters between the fixed teeth and the moving teeth in a crushing device according to one embodiment of the present invention. [Figure 6] FIG. 13 is an explanatory diagram of a state in which the swing jaws are operated by driving a fluid pressure motor when a foreign object has entered between the fixed teeth and the movable teeth in the crushing device according to one embodiment of the present invention. [Figure 7] 13 is an explanatory diagram showing a state in which the swing jaw is displaced away from the fixed teeth due to operation of a fluid pressure cylinder when a foreign object has entered between the fixed teeth and the moving teeth in the crushing device according to one embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A crushing device according to one embodiment of the present invention will be described below with reference to Figures 1 to 7. In this embodiment, an example of a single toggle type jaw crusher will be described. In each of the above figures, the crushing device 1 of this embodiment is configured to include a fixed tooth 11 fixed to a main body frame 10, a movable tooth 12 arranged opposite the fixed tooth 11, a swing jaw 13 to which the movable tooth 12 is attached and which is arranged on the main body frame 10 so as to be at least swingable, a fluid pressure cylinder 16 as the adjustment unit that positions the movable range of the swing jaw 13 relative to the main body frame 10 and makes it possible to adjust the distance between the fixed tooth 11 and the movable tooth 12, an electric motor 17 that moves the swing jaw 13 and the movable tooth 12, a fluid pressure motor 18 that moves the swing jaw 13 separately from the electric motor 17, and a control unit 19 that controls the fluid pressure cylinder 16, the electric motor 17, and the fluid pressure motor 18 in response to fluctuations in the load on the movable tooth 12 during crushing.

[0025] This crushing device 1 moves movable teeth 12 together with swing jaws 13 relative to fixed stationary teeth 11, periodically changing the distance between the stationary teeth 11 and the movable teeth 12, thereby crushing the object to be crushed that is supplied and introduced between the stationary teeth 11 and the movable teeth 12.

[0026] The crushing device 1 further has, as a mechanism for moving the swing jaw 13, a toggle plate 14 with one end abutting the lower part of the swing jaw 13, and a toggle block 15 which is abutting the other end of the toggle plate 14 and is mounted on the main frame 10 so as to be adjustable in position.

[0027] The mechanisms of each part of the crushing device are similar to those of a known single toggle type jaw crusher, except for the support structure of the toggle block 15 on the main frame 10, the fluid pressure circuit that operates the fluid pressure cylinder 16, and the control unit 19 that controls the fluid pressure cylinder 16, etc., and therefore detailed explanations will be omitted.

[0028] The stationary tooth 11 and the moving tooth 12 are each formed in a flat plate shape, and each surface is configured as a protruding surface with a plurality of protrusions arranged in parallel to form a wavy cross section. These fixed teeth 11 are disposed opposite to the movable teeth 12 attached to the swing jaw 13. Then, between the fixed teeth 11 and the movable teeth 12, a crushing space is formed which is narrow below and wide above.

[0029] The main body frame 10 has a highly rigid three-dimensional structure, for example, made of a metal framework or plate assembly, and is fixedly installed on a stable ground or floor, or may be mounted on a self-propelled cart. This main body frame 10 supports the fixed teeth 11 and the swing jaw 13 to which the movable teeth 12 are attached.

[0030] A rotating shaft 20 for supporting the swing jaw 13 is rotatably supported on the upper part of the main body frame 10. An eccentric shaft portion 21 that is eccentric from the center of the rotating shaft is integrally provided on this rotating shaft 20, and the upper end of the swing jaw 13 is attached relatively rotatably around this eccentric shaft portion 21. As with known jaw crushers, a flywheel 25 and a pulley (not shown) to which driving force from the electric motor 17 is transmitted via an endless belt are attached to the end of the rotating shaft 20.

[0031] During normal crushing, the rotating shaft 20 is rotated by the electric motor 17. When an excessive current may flow through the electric motor due to a large load, such as at start-up, the rotating shaft 20 is driven by the fluid pressure motor 18, and after the rotation speed increases, the driving is switched to the electric motor 17.

[0032] The swing jaw 13 has an upper portion supported by an eccentric shaft portion 21 of a rotating shaft 20, and is biased in a direction away from the stationary tooth 11 by a tension rod 30 connected to the lower end portion.

[0033] The swing jaw 13 has its upper portion supported by the eccentric shaft portion 21 of the rotating shaft 20, while its lower recess is abutted against one end of a toggle plate 14 that is separately provided on the main frame 10 so as to be able to swing, and is biased in a direction away from the stationary tooth 11 by a tension rod 30 connected to the lower end so as to maintain this abutment.

[0034] The toggle plate 14 is a generally rectangular metal plate that is arranged parallel to the axial direction of the rotating shaft 20 (the front direction in FIG. 1) (see FIG. 1). One end of the toggle plate 14 is adapted to abut against a recess in the lower part of the swing jaw 13 so as to be able to swing.

[0035] The toggle block 15 is arranged on the main body frame 10 so that its movable direction is restricted by a part of the main body frame 10 so as to move forward and backward relative to the swing jaw 13, and is connected to a fluid pressure cylinder 16 so as to be normally immobile. The other end of the toggle plate 14 is adapted to abut against a recess provided in the toggle block 15 so as to be able to swing.

[0036] By biasing the swing jaw 13 in a direction away from the stationary teeth 11, the toggle plate 14 is positioned between the swing jaw 13 and the toggle block 15, and one end of the swing jaw 13 and the toggle plate 14, and the other end of the toggle block 15 and the toggle plate 14 are respectively brought into contact with each other and maintained in a state where they are not separated from each other. In this way, the swing jaw 13, the toggle plate 14, the main frame 10, and the rotating shaft 20 form a kind of link mechanism.

[0037] When the rotating shaft 20 is rotated by the drive of the electric motor 17 or the fluid pressure motor 18, the swing jaw 13 repeats a predetermined movement approaching and moving away from the stationary tooth 11, which not only oscillates but also moves up and down, based on the characteristics of the link mechanism.

[0038] The fluid pressure cylinder 16, as the adjustment unit, is disposed at a predetermined location on the main frame 10 opposite the side of the swing jaw 13 where the fixed tooth 11 is located, with one end attached to an end of the toggle block 15 and the other end attached to an end of the main frame 10, and the distance between these ends can be varied by fluid pressure control. This adjusts the position of the toggle block 15 relative to the main frame 10, thereby positioning the swing jaw 13 linked to it and the moving tooth 12 integrated with it relative to the main frame 10, making it possible to adjust the distance between the fixed tooth 11 and the moving tooth 12.

[0039] The fluid pressure cylinders 16 are arranged in a plurality (for example, three) on the side of the main frame 10 opposite the side on which the fixed teeth 11 are located with respect to the swing jaw 13, in a direction parallel to the axial direction of the rotating shaft 20.

[0040] The gap between the stationary teeth 11 and the moving teeth 12, which relates to the particle size of the crushed pieces desired to be obtained by crushing the object to be crushed by the crushing device, is adjusted by adjusting the position of the toggle block 15 with the fluid pressure cylinder 16, moving the swing jaw 13 and the moving teeth 12 via the toggle plate 14, and when the specified gap corresponding to the size of the crushed pieces is obtained, the fluid pressure cylinder 16 is brought to a stationary state and the toggle block 15 is fixed on the main frame 10.

[0041] In addition, when there is an abnormality where crushing is stalled between the fixed teeth 11 and the moving teeth 12, that is, when the load on the moving teeth 12 increases due to the presence of an object to be crushed that is crushable but difficult to crush, or an uncrushable foreign object during crushing, the fluid pressure cylinder 16, under the control of the control unit 19, reduces the gap between one end and the other end of the fluid pressure cylinder 16 and moves the toggle block 15 in a direction away from the fixed teeth 11, temporarily widening the gap between the fixed teeth 11 and the moving teeth 12, and promoting the crushing of the object to be crushed and the discharge of the foreign object from between the fixed teeth 11 and the moving teeth 12.

[0042] The electric motor 17 is disposed at a location away from the rotating shaft 20 and transmits driving force to a pulley at the end of the rotating shaft 20 via an endless belt, thereby rotating the rotating shaft 20 and moving the swing jaw 13 and the movable teeth 12 attached thereto.

[0043] The fluid pressure motor 18 is attached to the upper part of the main body frame 10, and its output shaft is connected to the rotating shaft 20 via a flywheel 25 at the end of the rotating shaft 20, and drives the rotating shaft 20 to rotate separately from the electric motor 17, thereby moving the swing jaw 13 and the moving teeth 12 attached thereto.

[0044] During crushing, when the load on the moving teeth 12 increases due to an uncrushable foreign object and crushing is interrupted, this fluid pressure motor 18 is controlled by the control unit 19 to repeatedly rotate the rotating shaft 20 forward and backward in small increments, and this forward and reverse rotation moves the swing jaw 13, repeatedly changing the distance between the fixed teeth 11 and the moving teeth 12.

[0045] The control unit 19 controls the fluid pressure cylinder 16 as the adjustment unit, and the electric motor 17 and fluid pressure motor 18 that move the swing jaw 13 and the moving teeth 12 in response to fluctuations in the load on the moving teeth 12 during crushing.

[0046] When the load on the moving teeth 12 increases due to a crushable object or an uncrushable foreign object present between the fixed teeth 11 and the moving teeth 12 during crushing, the control unit 19 reduces the gap between one end and the other end of the fluid pressure cylinder 16 to move the swing jaw 13 and increase the gap between the fixed teeth 11 and the moving teeth 12, thereby reducing the load. After the object that caused the increase in load is crushed, or after the foreign object is discharged from between the fixed teeth 11 and the moving teeth 12, the fluid pressure cylinder 16 is returned to its original state.

[0047] In detail, the control unit 19 includes a fluid pressure control means 19a, an electric motor control means 19b, and a fluid pressure control mechanism unit 19c. During crushing, when the load on the moving teeth 12 increases due to the crushable object to be crushed, the force tending to reduce the distance between one end and the other end of the fluid pressure cylinder 16 through the swing jaw 13 increases, and the fluid pressure in the fluid pressure circuit leading to the fluid pressure cylinder 16 increases. In this way, the fluid pressure control means 19a controls the working fluid in the fluid pressure circuit so that the distance between one end and the other end of the fluid pressure cylinder is temporarily reduced, thereby making it possible to suppress the load on the moving teeth.

[0048] This fluid pressure control means 19a can be, for example, an accumulator provided in communication with a flow path on the side where the fluid pressure increases with the contraction direction operation of the fluid pressure cylinder 16 in the fluid pressure circuit (for example, in the case of a double-acting single-rod type fluid pressure cylinder, a flow path leading to the cylinder chamber on the cap side). When an accumulator is used, when a temporary increase in the fluid pressure of the fluid pressure circuit leading to the fluid pressure cylinder 16 due to an increase in load is eliminated, the working fluid once taken in is returned to the flow path of the fluid pressure circuit, and the fluid pressure cylinder 16 is returned to its original state as it is, so that it is not necessary to adjust the setting of the interval between one end and the other end of the fluid pressure cylinder 16 related to the positioning of the swing jaw 13 or the setting of the holding pressure of the fluid pressure cylinder 16, and the effort and cost involved in such adjustments can be reduced.

[0049] In addition, similar to the accumulator, other control means can be used as long as it has a mechanism that allows a portion of the working fluid to temporarily escape to the flow path of the fluid pressure circuit when the fluid pressure in the fluid pressure circuit leading to the fluid pressure cylinder 16 increases, thereby allowing the fluid pressure cylinder to operate in the contraction direction, and that allows a portion of the released working fluid to be quickly returned to the flow path of the fluid pressure circuit when the fluid pressure decreases.

[0050] The motor control means 19b detects the current flowing through the motor 17, and if the detected current value satisfies a predetermined condition (for example, the current value exceeds a threshold value set corresponding to an overload) that corresponds to a situation in which an uncrushable foreign object enters between the fixed tooth 11 and the moving tooth 12, causing an overload on the moving tooth, the motor control means 19b stops driving the motor 17, whereas if the detected current value does not satisfy the condition, the motor control means 19b continues driving the motor 17.

[0051] In addition, the motor control means 19b may stop a feeder (not shown) that is provided upstream of the crushing device 1 and supplies the material to be crushed to the crushing device 1 in conjunction with stopping the driving of the motor 17.

[0052] In contrast to this type of motor control means 19b, when the load on the moving teeth 12 increases transiently due to a crushable object to be crushed, the fluid pressure control means 19a controls the working fluid to temporarily reduce the distance between one end and the other end of the fluid pressure cylinder 16 to such an extent that the current value of the motor 17 detected by the motor control means 19b does not reach a state that satisfies the above-mentioned condition, thereby suppressing the load.

[0053] For example, if a condition corresponding to an overload situation is set such that the current value flowing through the motor 17 exceeds 300A for 0.6 seconds, as shown in Figure 5, a foreign object that cannot be crushed actually gets stuck between the fixed tooth 11 and the moving tooth 12, interfering with the movement of the moving tooth 12. Even if the load on the moving tooth 12 increases transiently due to the object to be crushed and the pressure (toggle pressure) applied to the fluid pressure cylinder 16 rises to a peak, the fluid pressure control means 19a temporarily reduces the distance between one end and the other end of the fluid pressure cylinder 16, changing the positional relationship between the fixed tooth 11 and the toggle block 15, shown as the toggle set, and the swing jaw 13 and the moving tooth 12 are moved away from the fixed tooth 11, thereby suppressing the load on the moving tooth and preventing the current value (jaw current) of the motor 17 from satisfying the above condition corresponding to an overload situation.

[0054] The fluid pressure control mechanism 19c constitutes a main part of the fluid pressure circuit, and controls the operation of the fluid pressure cylinder 16 and the fluid pressure motor 18. In the control unit 19, when the load on the moving teeth increases due to an uncrushable foreign object, before the fluid pressure cylinder 16 widens the gap between the stationary teeth 11 and the moving teeth 12, the control unit 19 stops driving the swing jaw 13 via the rotating shaft by the electric motor 17, and the fluid pressure control mechanism unit 19c causes the fluid pressure motor 18 to rotate the rotating shaft 20 forward and backward to move the swing jaw 13, thereby repeatedly changing the gap between the stationary teeth 11 and the moving teeth 12 (see Figure 6).

[0055] This makes it easier for foreign matter, which is causing an increase in load between the fixed teeth 11 and the moving teeth 12, to be expelled from between the fixed teeth 11 and the moving teeth 12. In this case, the purpose is to expel foreign matter, and so the torque at startup is important, but since a lower rotation speed than for normal crushing is no problem as long as the rotating shaft 20 can be rotated forward and backward, the fluid pressure motor 18 does not need to have the capacity to handle crushing, and the fluid pressure motor 18 and the fluid pressure circuit for operating it can be made smaller.

[0056] If the foreign matter is not discharged from between the fixed teeth 11 and the moving teeth 12 even when the fluid pressure motor 18 is operated, the fluid pressure control mechanism 19c stops the fluid pressure motor 18, shortens the gap between one end and the other end of the fluid pressure cylinder 16, moves the swing jaw 13, and widens the gap between the fixed teeth 11 and the moving teeth 12 (see FIG. 7). After the foreign matter that caused the increase in load is discharged from between the fixed teeth 11 and the moving teeth 12, the fluid pressure cylinder 16 is returned to its original state.

[0057] Next, we will explain how the crusher based on the above configuration responds to overload during operation. As a premise, the crusher 1 is in a state where the swing jaws 13 are smoothly moved by the electric motor 17 to crush the object to be crushed, and the object can be continuously crushed between the fixed teeth 11 and the movable teeth 12 without any hindrance.

[0058] Also, before crushing the object to be crushed, the gap between the fixed teeth 11 and the movable teeth 12 is adjusted in advance. In this gap adjustment, under the control of the control unit 19, the fluid pressure cylinder 16 is operated to move the toggle block 15 relative to the main body frame 10, and the swing jaw 13 linked to this via the toggle plate 14 and the movable teeth 12 integrated therewith are also moved, so that the gap between the fixed teeth 11 and the movable teeth 12 becomes a value corresponding to the size of the crushed pieces to be obtained. When the size of the gap between the fixed teeth 11 and the movable teeth 12 becomes a desired value, the position adjustment (movement) of the toggle block 15 by the fluid pressure cylinder 16 stops, and the adjustment is completed.

[0059] In the crushing process after the gap adjustment is completed, the crushing operation of the crushing device is started by first rotating the rotating shaft 20 by the fluid pressure motor 18. When the rotating shaft 20 reaches an appropriate rotation speed, the electric motor 17 switches to a state where it rotates the rotating shaft 20, and the driving by the fluid pressure motor 18 is stopped. With such rotation of the rotary shaft 20, the swing jaw 13, together with the movable teeth 12, repeats a predetermined movement of approaching and moving away from the stationary teeth 11.

[0060] A feeder (not shown) is provided above the crushing device 1, which performs the crushing, to supply the material to be crushed to the crushing device 1. The material to be crushed is supplied and introduced into the crushing space between the fixed teeth 11 and the movable teeth 12 by this feeder.

[0061] The object to be crushed is inserted between the fixed teeth 11 and the movable teeth 12 and is subjected to a clamping pressure from the fixed teeth 11 and the movable teeth 12 due to the movement of the swing jaw 13. This pressure causes stress to be concentrated on a part of the object to be crushed, and the object is crushed and divided starting from the point of stress concentration.

[0062] As the material to be crushed moves from top to bottom through the crushing space between the fixed teeth 11 and the moving teeth 12, it is subjected to the crushing force and is crushed into smaller particles, and this process is repeated until crushed pieces of the desired size are finally discharged from the lower end (discharge outlet) of the gap between the fixed teeth 11 and the moving teeth 12.

[0063] During operation of the crushing device, the load on the moving teeth 12 that move to crush the material becomes the rotation load of the rotating shaft 20 that drives the moving teeth 12 together with the swing jaw 13, and is reflected as the current value flowing through the electric motor 17, and this current value is monitored by the electric motor control means 19b of the control unit 19. Furthermore, an increase in the load on the moving teeth 12 acts on the swing jaw 13 as an apparent force that tries to widen the gap between the stationary teeth 11 and the moving teeth 12, and through the toggle plate 14 and toggle block 15 that support the swing jaw 13 from the rear, it further acts as a force that tries to compress the fluid pressure cylinder 16, resulting in an increase in the fluid pressure of the working fluid in a part of the fluid pressure circuit including the fluid pressure cylinder 16. This increase in fluid pressure in the fluid pressure circuit is reflected in the fluid pressure control means 19a of the control unit 19.

[0064] During this operation, if the crushable object is not crushed smoothly between the fixed teeth 11 and the moving teeth 12, or if the load on the moving teeth 12 increases due to the presence of uncrushable foreign objects, the crushing movement of the moving teeth 12 and the swing jaw 13 will be impeded, leading to an abnormality in the rotation load of the rotating shaft 20 that prevents the swing jaw 13 from moving properly, and a corresponding increase in the current value of the electric motor 17. Also, due to the increase in load, a force that tries to compress the fluid pressure cylinder 16 acts through the swing jaw 13 and other parts, and the fluid pressure in the fluid pressure circuit increases.

[0065] During crushing, when a crushable object has difficult-to-crush properties and is not crushed smoothly, there is a transient increase in the load on the moving teeth 12. In response to an increase in the fluid pressure in the fluid pressure circuit leading to the fluid pressure cylinder 16, the fluid pressure control means 19a of the control unit 19 controls the fluid pressure circuit to temporarily release a portion of the working fluid to the space outside the flow path of the fluid pressure circuit, thereby allowing the fluid pressure cylinder 16 to operate in the contraction direction, and temporarily reduce the distance between one end and the other end of the fluid pressure cylinder 16.

[0066] In this way, by temporarily reducing the distance between one end and the other end of the fluid pressure cylinder 16, the toggle block 15 and the swing jaw 13 linked to it are moved in a direction away from the fixed tooth 11, temporarily widening the distance between the fixed tooth 11 and the moving tooth 12 (see Figure 4), thereby alleviating the load acting on the moving teeth as a reaction force from the objects to be crushed and changing the positional relationship between the objects to be crushed and the fixed tooth 11 and moving tooth 12, thereby promoting the crushing of the objects to be crushed.

[0067] When the uncrushed objects are crushed and the load on the moving teeth 12 is reduced, the reaction force from the objects to be crushed against the movement of the moving teeth 12 and swing jaw 13 also returns to its original state, so that the force compressing the fluid pressure cylinder 16 from the set state does not act as much as before, and as the fluid pressure in the fluid pressure circuit decreases, the fluid pressure control means 19a quickly returns some of the released working fluid to the flow path of the fluid pressure circuit, restoring the distance between one end and the other end of the fluid pressure cylinder 16 to its original state. Accordingly, the distance between the stationary teeth 11 and the moving teeth 12 also returns to the initial set state.

[0068] In this case, the fluid pressure control means 19a controls the working fluid to temporarily reduce the distance between one end and the other end of the fluid pressure cylinder 16 in response to the transient increase in load on the moving teeth 12, thereby suppressing the load, so that the current value of the electric motor 17 detected by the electric motor control means 19b does not reach a state that satisfies the condition corresponding to an overload, and the electric motor 17 does not stop.

[0069] On the other hand, when an increase in the load on the moving teeth 12 occurs due to the presence of an uncrushable foreign object between the fixed teeth 11 and the moving teeth 12 during crushing, the motor control means 19b of the control unit 19 continues to drive the motor 17 until the initial current value of the motor 17 detected by the motor control means 19b of the control unit 19 satisfies the condition corresponding to the situation in which the moving teeth are overloaded.

[0070] When the motor control means 19b determines that the detected current value of the motor 17 has reached the condition corresponding to the overload, the drive of the motor 17 is stopped. At this time, the feeder is also stopped so that the crushing object is not supplied to the crushing device 1.

[0071] Further, the fluid pressure control mechanism portion 19c of the control unit 19 operates the fluid pressure motor 18, and rotates the rotary shaft 20 forward and backward by this fluid pressure motor 18 to move the swing jaw 13, and repeatedly changes the interval between the fixed tooth 11 and the moving tooth 12 (see FIG. 6). In this way, foreign matter staying between the fixed tooth 11 and the moving tooth 12 and causing an overload state is made easier to be discharged from between the fixed tooth 11 and the moving tooth 12.

[0072] When foreign matter is discharged from between the fixed tooth 11 and the moving tooth 12 by the forward and reverse rotation drive of this fluid pressure motor 18, the fluid pressure motor 18 is operated in the same manner as at the start of the operation related to crushing, and then the motor 17 is operated, and the supply of the crushing object by the feeder is restarted to return to the crushing operation state.

[0073] Even when receiving the movement of the moving tooth 12 accompanying the forward and reverse rotation drive of the fluid pressure motor 18, if foreign matter is not discharged from between the fixed tooth 11 and the moving tooth 12, the fluid pressure control mechanism portion 19c of the control unit 19 controls the fluid pressure of each flow path connected to the fluid pressure cylinder 16 in the fluid pressure circuit, operates the fluid pressure cylinder 16 in the contraction direction, and reduces the interval between one end and the other end of the fluid pressure cylinder 16. In this case, the interval between one end and the other end of the fluid pressure cylinder 16 is made smaller than in the case of a transient increase in the load caused by the fact that the crushable crushing object is not smoothly crushed.

[0074] In this way, the gap between one end and the other end of the fluid pressure cylinder 16 is reduced, and the toggle block 15 and the swing jaw 13 linked thereto are moved in a direction away from the fixed tooth 11, thereby widening the gap between the fixed tooth 11 and the moving tooth 12, making it easier to discharge foreign matter from between the fixed tooth 11 and the moving tooth 12 (see FIG. 7). If the foreign matter is not discharged from the discharge port at the lower end of the space between the fixed tooth 11 and the moving tooth 12, the fluid pressure motor 18 may be stopped in advance to stop the movement of the swing jaw 13 and the moving tooth 12, and then the foreign matter may be removed from the upper side of the space between the fixed tooth 11 and the moving tooth 12.

[0075] When the foreign object is discharged from between the fixed teeth 11 and the movable teeth 12, if the interval between one end and the other end of the fluid pressure cylinder 16 was narrowed, the fluid pressure control mechanism 19c of the control unit 19 controls the fluid pressure of each flow path connected to the fluid pressure cylinder 16 in the fluid pressure circuit so as to return the interval to the original interval, and the fluid pressure cylinder 16 is operated in the extension direction, and the interval between the fixed teeth 11 and the movable teeth 12 is returned to the setting state for the crushing operation. Then, similar to the start of the crushing operation, the fluid pressure motor 18 drives the rotating shaft 20, and when the rotating shaft 20 reaches an appropriate rotation speed, the electric motor 17 transitions to a state in which the rotating shaft 20 is rotated and driven, and the operation state for the crushing operation is restored in which the swing jaw 13 approaches and moves away from the fixed teeth 11 together with the movable teeth 12 as the rotating shaft 20 rotates. Then, the supply of the objects to be crushed between the stationary teeth 11 and the movable teeth 12 by the feeder is resumed, and the crushing operation state is restored.

[0076] In the crushing device 1, the motor control means 19b of the control unit 19 detects the current value of the motor 17 during crushing, and in response to a transient increase in the load on the moving teeth 12 caused by a crushable object being difficult to crush due to its difficult nature and not being crushed smoothly, the fluid pressure control means 19a of the control unit 19 temporarily reduces the distance between one end and the other end of the fluid pressure cylinder 16 to suppress the load and not stop the motor 17. In addition, in the case of an increase in the load on the moving teeth 12 caused by the presence of an uncrushable foreign object, the current value of the motor 17 detected by the motor control means 19b satisfies the condition corresponding to an overload, and the motor control means 19b stops the motor 17.

[0077] In this way, foreign matter, which is mainly metal, can be detected with high accuracy based on the current value of the motor 17 and recovered from the crushing device 1 where crushing has been suspended due to the stopping of the motor 17, and it is possible to prevent metallic foreign matter from flowing out to the downstream side of the crushing device. Even if a secondary crushing device is used in the process following the crushing device, the crushing device can function as a metal detector, so to speak, and can prevent metallic foreign matter from being introduced into the secondary crushing device, eliminating the need to install a metal detector between the crushing device and the secondary crushing device to protect the secondary crushing device, thereby reducing costs in the entire process related to crushing.

[0078] When the current value of the electric motor 17 detected by the electric motor control means 19b satisfies the above-mentioned condition corresponding to an overload, the control unit 19 stops the drive of the electric motor 17, while starting the fluid pressure motor 18 again, and rotates the rotary shaft 20 forward and backward with the fluid pressure motor 18 to move the swing jaw 13 and repeatedly change the gap between the stationary teeth 11 and the moving teeth 12. However, this is not limiting, and even if the swing jaw 13 and the moving teeth 12 are moved by the drive of the fluid pressure motor 18, it is extremely difficult for foreign matter to be discharged from between the stationary teeth 11 and the moving teeth 12. In the case where an overload is anticipated from the beginning when the overload is recognized, the control unit 19 does not operate the fluid pressure motor 18, and simultaneously with or immediately after the driving of the electric motor 17 is stopped, the fluid pressure control mechanism unit 19c controls the fluid pressure of each flow path connected to the fluid pressure cylinder 16 in the fluid pressure circuit to reduce the gap between one end and the other end of the fluid pressure cylinder 16, and moves the swing jaw 13 in a direction away from the fixed tooth 11 to increase the gap between the fixed tooth 11 and the moving tooth 12, thereby making it easier to expel foreign matter from between the fixed tooth 11 and the moving tooth 12.

[0079] Furthermore, when the motor control means 19b detects a state in which the current value of the motor 17 satisfies the condition corresponding to overload and stops the drive of the motor 17, separately from this, when the fluid pressure in the fluid pressure circuit leading to the fluid pressure cylinder 16 increases to a predetermined upper limit value due to an increase in the load, the fluid pressure control mechanism section 19c of the control section 19 performs control to release the fluid pressure to the low pressure side, thereby reducing the distance between one end and the other end of the fluid pressure cylinder 16 and widening the distance between the fixed teeth 11 and the moving teeth 12 to promote the discharge of foreign matter. In this case, as a main part of the fluid pressure control mechanism section 19c, for example, a relief valve is provided in the fluid pressure circuit leading to the fluid pressure cylinder 16, and when the fluid pressure increases and exceeds the set pressure, the relief valve operates to release the fluid pressure to the low pressure side, or a predetermined fluid control means is provided in the fluid pressure circuit, and when the fluid pressure reaches the upper limit value, a control operation to release the fluid pressure to the low pressure side can be executed. By performing control with the fluid pressure control mechanism section 19c based on the fluid pressure that changes following the change in the load without delay, effective and rapid measures can be taken against an abnormal state, such as automatically widening the distance between the fixed teeth 11 and the moving teeth 12 in response to an increase in the load due to foreign matter during crushing.

[0080] In this way, in the crushing device of this embodiment, even if the load on the moving teeth 12 that move during crushing increases due to a crushable object to be crushed or an uncrushable foreign object that has fallen between the fixed teeth 11 and the moving teeth 12, the fluid pressure cylinder 16, which serves as an adjustment unit, displaces the swing jaw 13 and widens the space between the fixed teeth 11 and the moving teeth 12, thereby preventing a further increase in load and enabling the object to be crushed or the foreign object to be discharged. After the crushing or discharge is completed, the fluid pressure cylinder 16 returns the space between the fixed teeth 11 and the moving teeth 12 to its original state, making it possible to continue crushing. Therefore, in the case of a crushable object to be crushed, the device does not stop due to the increased load, and the moving teeth 12 can be quickly returned to its original state by the movement of the fluid pressure cylinder 16, so that the crushed object obtained by crushing can be maintained at the desired size without any problems, and the crushing operation can be performed efficiently and accurately. In addition, even if the load increases due to an uncrushable foreign object, resulting in an overload, the fluid pressure cylinder 16 can widen the gap between the fixed tooth 11 and the moving tooth 12, and after the foreign object has been expelled, the fluid pressure cylinder 16 can quickly return the gap between the fixed tooth 11 and the moving tooth 12 to its original position. This minimizes interruptions to crushing, reduces losses, and prevents large uncrushed objects from leaking out.

[0081] In the crushing device according to the embodiment, even if an increase in the load on the moving teeth 12 occurs, the motor control means 19b of the control unit 19 continues to drive the motor 17 as long as the current value of the motor 17 detected by the motor control means 19b of the control unit 19 does not satisfy the condition corresponding to the situation where the moving teeth 12 are overloaded. Until the current value satisfies the condition corresponding to the overload and the drive of the motor 17 is stopped, the control unit 19 does not perform any particular control other than the control on the fluid pressure circuit side. However, this is not limited to this, and the motor control means of the control unit may be configured to preset a second threshold value, which is a current value flowing through the motor when an increase in the load on the moving teeth occurs and is smaller than the current value when the condition corresponding to the overload situation is satisfied, and when the current value of the motor detected by the motor control means exceeds this second threshold value, the drive of the motor may continue while the feeder supplying the material to be crushed to the crushing device may be stopped.

[0082] In this case, when the load on the moving teeth increases due to the hard-to-shred objects or the foreign objects that cannot be crushed, and the current value of the motor detected by the motor control means exceeds the second threshold, the feeder stops supplying the objects to the crushing device. In the case of hard-to-shred objects, when the objects are crushed and the current value of the motor falls below the second threshold based on the reduction in the load on the moving teeth, the feeder resumes supplying the objects to be crushed. On the other hand, in the case of foreign objects, when the load continues to increase due to failure to crush and the current value meets the above-mentioned condition corresponding to overload, the motor is stopped. After that, the foreign objects are discharged from between the fixed teeth and the moving teeth, and when the motor is driven to rotate the rotating shaft to return to the operating state during crushing, in which the swing jaw approaches and moves away from the fixed teeth together with the moving teeth, the feeder resumes supplying the objects to be crushed between the fixed teeth and the moving teeth.

[0083] In this way, if the current value of the motor detected by the motor control means exceeds the second threshold value even if it does not satisfy the conditions corresponding to an overload, the drive of the motor is not stopped, but the feeder is stopped and the supply of the objects to be crushed is interrupted.By doing this, while the load on the moving teeth increases and the progress of crushing of the objects to be crushed slows down, no more objects to be crushed are supplied between the fixed teeth and the moving teeth, and the crushing of the objects that are difficult to crush that caused the increase in load or the discharge of foreign matter can be concentrated.The crushing or discharge can be carried out quickly without being affected by the objects to be crushed supplied later, and the increased load state can be resolved in a shorter time and the crushing operation can be continued or resumed.

[0084] In addition, instead of controlling the feeder to stop based on the current value of the motor detected by the motor control means, the pressure (toggle pressure) applied to the fluid pressure cylinder that holds the position of the toggle block can be monitored, and the feeder can be controlled to stop when the pressure applied to the fluid pressure cylinder exceeds a predetermined threshold due to an increase in load caused by objects that are difficult to crush or foreign objects that cannot be crushed. In this case, the feeder can be stopped at a more appropriate time based on the clear appearance of a pressure rise state in the fluid pressure circuit in response to an increase in load, and the supply by the feeder can be appropriately adapted to the situation of the crushing device, allowing the crushing device to safely continue crushing. [Explanation of symbols]

[0085] 1 Crushing equipment 10 Main frame 11 Immovable teeth 12 Moving teeth 13 Swing Jaw 14 Toggle Plate 15 Toggle Block 16 Fluid pressure cylinder 17 Electric motor 18 Fluid pressure motor 19 Control section 19a Fluid pressure control means 19b Motor control means 19c Fluid pressure control mechanism 20 Rotational Axis 21 Eccentric shaft part 25 Flywheel 30 Tension Rod

Claims

1. A crushing device which is a jaw crusher, comprising: a stationary tooth fixed to a main body frame; a movable tooth arranged opposite the stationary tooth; and a swing jaw to which the movable tooth is attached and which is at least swingably disposed on the main body frame, the movable tooth being moved together with the swing jaw relative to the stationary tooth to crush an object to be crushed placed between the stationary tooth and the movable tooth, an adjustment unit that adjusts the distance between the fixed teeth and the movable teeth by positioning the movable range of the swing jaw relative to the main body frame; An electric motor for moving the swing jaw and the moving teeth; A control unit that controls at least the adjustment unit in response to a change in load on the movable teeth during crushing, the adjustment unit is a fluid pressure cylinder disposed at a predetermined location on the opposite side of the swing jaw from the side where the fixed teeth are located, and the swing jaw is positioned by changing the distance between one end and the other end of the fluid pressure cylinder, thereby making it possible to adjust the distance between the fixed teeth and the movable teeth, The control unit: a fluid pressure control means for controlling the fluid while temporarily reducing the distance between one end and the other end of the fluid pressure cylinder when the load on the moving teeth increases, and a force that tries to reduce the distance between one end and the other end of the fluid pressure cylinder through the swing jaw becomes stronger and the fluid pressure in the fluid pressure circuit leading to the fluid pressure cylinder becomes high, thereby suppressing the load on the moving teeth; and a motor control means for detecting a current flowing through the motor, and stopping the operation of the motor when the detected current value satisfies a predetermined condition set in advance, which corresponds to a situation where an uncrushable foreign object gets between the stationary teeth and the moving teeth and causes an overload on the moving teeth, and continuing the operation of the motor when the detected current value does not satisfy the condition. When the load on the moving teeth increases due to a crushable object to be crushed or an uncrushable foreign object, the control unit reduces the distance between one end and the other end of the fluid pressure cylinder serving as the adjustment unit to move the swing jaw and increase the distance between the fixed teeth and the moving teeth, and after the object to be crushed that caused the increase in load is crushed or after the foreign object is discharged from between the fixed teeth and the moving teeth, the fluid pressure cylinder is returned to its original state. When a load on the movable teeth is transiently increased by a crushable object to be crushed, the fluid pressure control means controls the fluid in the fluid pressure circuit leading to the fluid pressure cylinder to such an extent that the current value of the electric motor detected by the electric motor control means does not reach a state satisfying the condition, thereby temporarily reducing the distance between one end and the other end of the fluid pressure cylinder. A crushing device characterized by the above.

2. The crushing device according to claim 1, A hydraulic motor is provided for moving the swing jaw separately from the electric motor, When the load on the moving teeth increases due to an uncrushable foreign object, the control unit stops the drive by the electric motor before the adjustment unit widens the gap between the stationary teeth and the moving teeth, and drives the fluid pressure motor in forward and reverse rotation to move the swing jaw, thereby repeatedly changing the gap between the stationary teeth and the moving teeth, so that the foreign object that caused the increase in load can be easily discharged from between the stationary teeth and the moving teeth. A crushing device characterized by the above.

3. In the crushing device according to claim 1 or 2, The motor control means of the control unit presets a second threshold value, which is a current value flowing through the motor when an increase in the load on the moving teeth occurs, and is smaller than the current value when the condition corresponding to an overload state is satisfied, The motor control means detects a current flowing through the motor, and when the detected current value does not satisfy the condition and exceeds the second threshold value, the motor is continued to be driven while the feeder that supplies the material to be crushed to the crushing device is stopped. A crushing device characterized by the above.

4. A crushing device which is a jaw crusher comprising: fixed teeth fixed to a main body frame; movable teeth arranged opposite the fixed teeth; and a swing jaw to which the movable teeth are attached and which is at least swingably disposed on the main body frame, the movable teeth being moved together with the swing jaw relative to the fixed teeth to crush an object to be crushed placed between the fixed teeth and the movable teeth, an adjustment unit that adjusts the distance between the fixed teeth and the movable teeth by positioning the movable range of the swing jaw relative to the main body frame; A control unit that controls at least the adjustment unit in response to a change in load on the movable teeth during crushing; An electric motor for moving the swing jaw and the moving teeth; The electric motor and a fluid pressure motor for moving the swing jaw separately are provided, When the load on the movable teeth increases due to a crushable object to be crushed, the control unit causes at least the adjustment unit to widen the gap between the stationary teeth and the movable teeth, and after the object to be crushed that caused the increase in load is crushed, the adjustment unit is returned to its original state; When the load on the moving teeth increases due to an uncrushable foreign object, the control unit stops the drive by the electric motor and drives the fluid pressure motor in forward and reverse rotation to move the swing jaw, repeatedly changing the gap between the stationary teeth and the moving teeth, making it easier for the foreign object that caused the increase in load to be discharged from between the stationary teeth and the moving teeth, and for foreign objects that are not discharged, further widens the gap between the stationary teeth and the moving teeth by at least the adjustment unit, and after the foreign object is discharged from between the stationary teeth and the moving teeth, returns the adjustment unit to its original state. A crushing device characterized by the above.

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