JPH0229376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vertical pulverizer that pulverizes cement raw materials, coal, chemicals, etc. through cooperation between a rotary table and rollers.

[Prior art]

2. Description of the Related Art Vertical crushers equipped with a rotary table and rollers are widely used as a type of crusher that finely crushes granules such as cement raw materials, coal, and chemicals into powder.

FIG. 1 is a vertical cross-sectional view of this type of vertical crusher, and the outline of its structure will be explained based on the figure. The vertical crusher 1 has a cylindrical casing 3 fixed on a base 2. A vertical motor-equipped speed reducer 4 is provided at the lower center of the casing 3. Reference numeral 5 denotes a rotary table that is directly connected to the upward-facing reducer output shaft and has an annular liner stuck to its upper end plane, and includes a supply cylinder 6 that protrudes upward from the casing 3.
The raw material supplied by the conveyor is configured to be supplied to the center of this rotary table 5. Reference numeral 7 denotes a plurality of bearings (four in this crusher) located at positions dividing the outside of the rotary table 5 into a plurality of equal parts in the circumferential direction and pivotably supported on the casing 3 side, A roller 8 formed in the shape of a truncated cone is supported on each bearing 7 with its peripheral surface facing the liner surface of the rotary table 5. A driving device 9 is attached to each of the rollers 9 to bring the roller 8 into contact with the rotary table 5 or to separate it from the rotary table 5.
That is, the hydraulic cylinder 10 is installed on the casing 3 side.
is pivotably supported in correspondence with each bearing 7, and the working end of the piston rod 11 and the pivot shaft 12 of the bearing 7 are connected by a connecting rod 13. Then, by supplying oil to the rod end side port 10C (hereinafter referred to as C port 10C) of the hydraulic cylinder 10 by a hydraulic device (not shown), the piston rod 11 moves back, the roller 8 is pressed against the rotary table 5, and the head end side port 10D
By supplying oil to the D port 10D (hereinafter referred to as D port 10D), the piston rod 11 moves forward and the roller 8 separates from the rotary table 5.

A discharge port 14 and a suction port 15 are opened at the upper and lower ends of the casing 3 and are connected to each other by a duct (not shown), and a suction fan and a hot air stove are installed in the duct. Due to the rotation, hot air enters the casing 3 through the suction port 15 and rises, and then is discharged from the discharge port 14 and circulated. Reference numeral 16 denotes a separator that is pivotally supported on the casing side, and is configured to classify the powder and granules that are crushed between the rotary table 5 and the rollers 8 and rise with the hot air into particles with a predetermined particle size or more and those with a predetermined particle size or less. It is configured. 17 is a hot air passage;
18 is an annular hot air blowing passage formed between the rotary table 5 and the wall surface of the casing 3.

With the above configuration, when the raw material is supplied from the supply tube 6 to the center of the rotary table 5 after starting the motorized speed reducer 4 and the suction fan, the raw material is transferred to the center of the rotary table 5 as the rotary table 5 rotates. Due to centrifugal force, it draws an arc-shaped trajectory toward the outer periphery of the table. At this time, pressure oil is being sent to the C port 10C and the roller 8 is in pressure contact with the rotary table 5, so the raw material directed toward the outer periphery of the table is caught between the roller 8 and the rotary table 5 and pulverized. is,
It deviates from the rotary table 5 and moves above the blow-up passage 18. Further, the raw material that has not been bitten by the roller 8 and has deviated from the outer periphery of the table also moves upward in the blow-up passage 18. At this time, the hot air sent from the suction port 15 is blown up inside the blow-up passage 18, so
The powder and granules that have moved here are blown up with hot air and rise inside the casing 3, and the separator 16
It is classified by contacting the blades of the As a result of the classification, fine powder with a predetermined particle size or less passes through the separator 16 and is discharged from the discharge port 14 together with hot air, and then is collected, and particles with a predetermined particle size or more fall onto the rotary table 5 and have the opportunity to be crushed again. is given.

In such a grinding operation, the rollers 8 are used to intervene when the raw material cannot be continuously and smoothly supplied to the grinder 1 due to a failure in the feed line to the grinder 1, for example. If the rotary table 5 continues to rotate while in direct contact with the liner surface (so-called metal touch), the liner of the roller 8 or the table 5 may be damaged because the liner of the roller 8 and table 5 is generally made of wear-resistant cast iron. Abnormal wear may occur, and the crusher 1
Since the crusher itself vibrates abnormally and interferes with the smooth movement of the crusher 1, it is necessary to avoid the occurrence of metal touches as much as possible.

Therefore, conventionally, the bearing 7 or the connecting rod 13
A mechanical stopper is provided on the swinging part of the roller 8 to prevent the roller 8 from descending excessively.
In a large crusher, the weight of the rollers 8, bearings 7, etc. is extremely large, and as a result, the inertia force increases, so in order to control this, the stopper must be large, increasing costs and occupying space. The disadvantage was that it increased.

Alternatively, a sensor such as a proximity switch or a vibration meter that detects a metal touch is provided in the drive system of the roller 8, and the signal generated by the sensor operates the hydraulic circuit to the hydraulic cylinder 10 to move the roller 8. Conventionally, it has been done to separate the rotary table 5, but this also had a problem in that the response was slow. That is, hydraulic cylinder 1
Both ports 10C and 10D of 0 are connected to the hydraulic pump and tank via electromagnetic switching valves, and during crushing work, the electromagnetic switching valves are switched to the C port 10C side, and the pressure oil flows directly to the C port 10C. It is sent to the C port 10C after being sent or temporarily stored in an accumulator. Also D
Port 10D is open to the tank via a solenoid switching valve. And when metal touch occurs,
The solenoid switching valve switches to D port 10D based on the signal from the sensor.
Since the C port is opened to the tank, pressure oil is sent to the head end side of the hydraulic cylinder, and the roller 8 is lifted. However, in such conventional devices, it takes time to fill the long pipe with oil and send it to the D port after the metal touch signal is issued, and the roller 8 cannot be lifted instantly. However, continuous metal touching not only causes damage to the rollers and liners or accelerates their wear, but also causes vibration and noise, which worsens the working environment. Also, in order to instantly lift the roller 8, a hydraulic pump with a large discharge capacity can be used, but this type of crusher has a hydraulic circuit that maintains hydraulic pressure with an accumulator or the like during the crushing operation. A hydraulic pump with a particularly large discharge capacity is unnecessary and wasteful.

[Summary of the invention]

The present invention has been made in view of the above points, and includes a pipe line leading from a switching valve that switches the oil supply path of the hydraulic cylinder for upper and lower crushing rollers between the rod end side and the head end side to the acumulator on the rod end side, and the head end side. A switching valve device is provided that short-circuits the pipeline with the port going to the port by a bypass, shuts off the bypass at all times, and connects the bypass by operating in response to a signal of abnormal approach of the crushing roller to the rotary table generated by a sensor. As a result, when an abnormal approach occurs, the pressure oil sent from the accumulator to the rod end side can be divided into two parts and sent to the rod end side and the head end side. By skillfully utilizing the pressure difference caused by the pressure receiving area difference between the two sides and the piston rod, it is possible to instantly move the piston rod to the head end side, making it possible to lift the crushing roller from the rotary table.
As a result, the present invention provides a vertical pulverizer that can improve the durability of the pulverizing roller and liner, and also prevent vibration of the machine stand. Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

FIG. 2 is a hydraulic circuit diagram showing an embodiment of the vertical crusher according to the present invention. Since the overall structure of the vertical crusher has been explained based on FIG. 1, the explanation thereof will be omitted, and the explanation will be given later using the same figure when necessary. A plurality of units (in this example, 4 units) in FIG.
The hydraulic cylinder 10 is equipped with a hydraulic system whose hydraulic circuit diagram is shown in FIG. That is,
A pair of C ports 10 provided in each hydraulic cylinder 10
Pipes 20 are connected to C, respectively, and these pipes 20 are collected into a pipe 21. Further, the pipes connected to the D port 10D of each hydraulic cylinder 10 are collected in a pipe 22, and this pipe 22 and the pipe 21 are connected to a pair of solenoid
They are connected to both ports of an electromagnetic switching valve 23 equipped with SOL ₁ and SOL ₂ , respectively. A check valve 24 is provided on the piping 21 to allow pressure oil to move only in the direction of the hydraulic cylinder 10, and a variable throttle 25 and a switching valve 23 are provided on the piping 22 to allow pressure oil to move only in the direction of the hydraulic cylinder 10. A check valve 26 is provided which allows the The other two ports of the electromagnetic switching valve 23 are the on-off valve 2.
A piping 28 having a check valve 29 and a piping 30 having a check valve 29 are connected to a hydraulic pump 32 directly connected to a motor 31 and a tank ₃₃ , respectively. is supplied to the C port 10C, and by operating the solenoid SOL ₂ , pressure oil is supplied to the D port 10D.
An accumulator 34 for storing pressure oil is provided in each of the pipes 20, and is configured to temporarily store the pressure oil sent through the pipes 21 and 20 before supplying it to the C port 10C. has been done. 35 is a pipe 3 branched from the pipe 21
6 is a relief valve that maintains the set pressure of the pressure oil in the piping 21 by releasing the pressure oil to the tank 33 when the pressure of the pressure oil heading toward the C port 10C exceeds the set pressure. 37 is a relief valve that maintains the pressure of the pressure oil flowing from the hydraulic pump 32 toward the electromagnetic switching valve 23 below a set pressure. 38 more
39 is a filter, 4 is a pressure gauge with a variable throttle and an on-off valve that displays the oil supply pressure from the hydraulic pump 32;
0 is an instrument.

From the pipe 22, a pipe 4 leads to the tank.
1 is branched, and a pilot check valve 43 is disposed within this pipe 41. Furthermore, a solenoid is installed in the pipe 42 branched from the pipe 21.
An electromagnetic switching valve 45 equipped with SOL ₃ and SOL ₄ is provided, and pressure oil is sent to C port 10C and transferred to roller 8.
When the solenoid SOL 3 is lowered and crushing work is being performed, the solenoid SOL ₃ is activated, the solenoid switching valve 45 is opened, and the pilot pressure is transferred to the pilot check valve 43.
By opening this, the inside of the pipe 22, ie, the D port 10D of the cylinder 10, is opened to the tank and becomes atmospheric pressure. Further, when the pressure oil is fed to the D port 10D to lift the roller 8, the solenoid SOL ₄ is activated, the electromagnetic switching valve 45 is closed, and the pilot check valve 43 is closed. When the roller 8 is lowered from the raised position at the start of the crushing operation, the solenoid SOL ₄ of the electromagnetic switching valve 45 is operated and the pilot check valve 43 is closed. 46 is a pressure gauge with a variable throttle and an on-off valve that displays the oil pressure inside the pipe 21. Furthermore, a pilot check valve 48 is provided in the pipe 47 branched from the pipe 42 and connected to the tank 33.
and a relief valve 49 that sets and regulates the oil pressure in the pipe 47, and a solenoid _SOL5 is provided between the pilot check valve 48 and the pipe 21.
An electromagnetic switching valve 50 is provided. When the roller 8 is lifted, the solenoid SOL ₅ is activated, the pilot check valve 48 is opened, and a portion of the pressure oil in the pipe 21 that has risen above the set pressure of the relief valve 49 is released to the tank 33. has been done.

In such a hydraulic circuit, a switching valve device is provided that divides the pressure oil accumulated in the accumulator 34 into two into the C port 10C side and the D port 10D side when the roller 8 abnormally approaches the top surface of the table 5. There is. In other words, the piping 21 on the C port 10C side
and the pipe 22 on the D port 10D side is the pipe 51
A pilot check valve 52 and a check valve 53 that allow pressure oil to move only in the direction of the pipe 22 are disposed within the pipe 51. The pilot check valve 52 has a roller 8. An electromagnetic switching valve 54 with a solenoid SOL ₆ that is activated by an abnormal approach signal is attached. The pilot check valve 52 is always closed as shown in the figure during the crushing operation in which pressure oil is sent to the C port 10C and hydraulic pressure is maintained in the piping 21 and the accumulator 34. When approaching abnormally, solenoid SOL ₆ is activated and solenoid switching valve 5 is activated.
4 is opened and pilot pressure is applied to the pilot check valve 52 to open it. At the same time, the solenoid SOL ₄ is activated and the pilot check valve 43 is closed. In this way, the pilot check valve 52 opens and the pilot check valve 43 closes.
The pressure oil held in the pipes 21, 51, 2
2 to the D port 10D at the same pressure and is divided into two ports 10C and 10D. In this case, the pressure-receiving area of the rod end side, which is the C port 10C side, of the hydraulic cylinder 10 is smaller than the head end side, which is the D port 10D side, by an amount of 11 points, so that when the same pressure oil is sent to both, the piston rod 11 moves to the rod end side, and the four rollers 8 are lifted up at some point. Shortly after the roller 8 is lifted, the metal touch condition is resolved and the solenoid SOL ₆ is turned OFF by the signal, and the solenoid SOL ₃ is immediately activated, and the pressure oil on the head end side is released to the tank 33, and the rod end is Pressure oil is supplied to the side (C port 10C side), the roller 8 is lowered, and crushing is restarted.

The operation of the hydraulic circuit configured as above will be explained. When the motor of the motorized reducer 4 is started and the rotary table 5 is rotated, and a predetermined amount of raw material is supplied onto the rotary table 5, the solenoid SOL ₁ of the electromagnetic switching valve 23 is activated and pressure oil is supplied via the pipe 21. is sent to the storage unit 34, and the storage unit 34
The roller 8 in the raised position is maintained at the set pressure and sent to the rod end side of the hydraulic cylinder 10.
descends and the crushing operation begins. Note that when the roller 8 descends from the raised position at the start of operation, the solenoid SOL ₄ of the electromagnetic switching valve 45
is activated, the pilot check valve 43 is closed, and the head side of the cylinder 10 (D port 10D
side) is sequentially collected into a tank 33 via a pipe 22, a throttle valve 25, an electromagnetic switching valve 23, and a pipe 30. After the roller 8 completes its descent onto the table 5, the solenoid SOL ₃ of the electromagnetic switching valve 45
is turned ON (the state shown in FIG. 2), the pilot check valve 43 opens, and the head side of the cylinder 10 (the D port 10D side) is opened to the tank 33.
At this time, the solenoids SOL ₅ and SOL ₆ of the electromagnetic switching valves 50 and 54 are turned off (the state shown in the figure), and the check valves 48 and 52 are closed. When the roller 8 is lowered and a predetermined period of time has elapsed since the start of the crushing operation, the solenoid of the electromagnetic switching valve 23 is activated.
SOL ₁ is turned OFF, and as shown in the figure, it is in a neutral state and the rod end side of cylinder 10 (C port 1
The oil on the 0C side is maintained at a predetermined hydraulic pressure between the check valve 24 in the pipe 21 and the rod end side of the cylinder 10, and thereafter the crushing operation is continued.

During the crushing operation, if the material to be crushed is no longer supplied to the crusher 1 due to a failure of the raw material feeder, for example, the material to be crushed should not be caught between the rollers 8 and the rotary table 5. As a result, when the roller 8 and the rotary table 5 become abnormally close to each other and a so-called metal touch occurs, a sensor such as a vibration meter in the proximity switch detects this and issues a signal, and the solenoids SOL ₆ and SOL ₄ are turned on. Solenoid SOL ₃ turns OFF. Therefore, the electromagnetic switching valve 54 opens and pilot pressure is applied, and the pilot check valve 52 opens.
Since the pilot pressure from the electromagnetic switching valve 45 is no longer applied, the pilot check valve 43 is closed. Accumulator 3, which had been held on the C port 10C side by opening and closing valves 52 and 43,
The pressure oil in 4 is connected to the pipes 21, 51 and the check valve 52,
53 and the pipe 22 to the D port 10D. In other words, a large amount of pressure oil stored in the accumulator 34 is transferred to both ports 10C and 1
It is instantly divided into two parts at the same pressure to 0D. In this case, the pressure receiving area on the rod end side, which is the C port 10C side, is smaller than the head end side, which is the D port 10D side, by the amount of the piston rod 11, so the piston rod 11 instantly moves to the rod end side, and the four rollers 8 is suddenly lifted up. This allows you to avoid metal touch. Soon, the material to be crushed will be supplied in the normal condition, the metal touch will be resolved, and a signal will be issued. Solenoids SOL ₆ and SOL ₄ will turn OFF, and solenoid SOL ₃ will turn ON (state shown). The pilot check valve 52 closes, the pilot check valve 43 opens, and the D port 10D is released to the tank 33, and the solenoid switching valve 23 opens.
SOL ₁ is activated and pressure oil is supplied from the pipe 21 to the C port 10C side. Therefore, the roller 8 is lowered and the crushing operation is restarted. In this way, when a metal touch occurs, the roller 8 is lifted by dividing the pressure oil in the accumulator 34 into two, so the process from the occurrence of a metal touch to the lifting of the roller 8 is completed instantly, and even after the metal touch is eliminated, the roller 8 is lifted automatically. After a short time, the rollers 8 are lowered and the crushing operation is resumed.

When interrupting or finishing the grinding operation, the solenoid
When SOL ₂ is turned on, the electromagnetic switching valve 23 switches and pressure oil flows from the pump 32 through the pipe 22 to the D port 1.
Sent to 0D side. At the same time, the solenoid
Since SOL ₃ is turned OFF and solenoid SOL ₄ is turned ON, the pilot check valve 43 is closed and the D port 10D side is not released to the tank 33 side. Further, at this time, the solenoid SOL ₅ is turned ON, so the pilot check valve 48 is opened, and a part of the pressure oil in the pipe 21 is released to the tank 33 through the pipe 42 . This causes the four rollers 8 to be lifted at any time.

The above is the 4 hydraulic cylinders 1 at the time of metal touch.
Although an embodiment has been shown in which the rollers 8 move simultaneously to lift four rollers 8 at the same time, another embodiment in which only the roller in which a metal touch has occurred is lifted will be described below. FIG. 3 is a hydraulic circuit diagram of such another embodiment, showing the hydraulic circuit and valves between the pipes 21 and 22 heading to the C port 10C and the D port 10D, respectively, and the hydraulic pump 32 and tank 33. Since the configuration is almost the same as that of the embodiment shown in FIG. 1, the same reference numerals are given and the explanation thereof will be omitted. In this embodiment, the electromagnetic switching valve 45, pilot check valve 43, and piping 41 shown in FIG. 2 are not provided. In the figure, the pipes 20 connected to the C port of each cylinder 10 are collected in a pipe 21, and each pipe 20
An accumulator 34 is connected to. Note that the number of accumulators 34 may be two as shown in FIG. 2, or may be more than that. Also, the D port 10 of each hydraulic cylinder 10
The pipes 61 connected to D are collected in the pipe 22, and each pipe 61 is provided with a check valve 62 that allows pressure oil to move only in the direction of the D port 10D. A switching valve device, generally indicated by the reference numeral 63, is provided in each bypass that short-circuits the piping 20 going to each C port 10C and the piping 61 heading to each D port 10D. That is, a piping 64 branched from the piping 20 is provided with an electromagnetic switching valve 65 equipped with a solenoid SOL ₇ , and pilot circuits 66 and 67 connected to both ports switched by the solenoid SOL ₇ ,
Pilot check valves 68 and 69 are connected, respectively. Of these, pilot check valve 68
is provided in the pipe 40 that connects the pipes 20 and 61, and when the solenoid SOL ₇ is turned ON by the metal touch signal explained in the prefilling example, it opens with pilot pressure and checks the pressure oil in the accumulator 24. It is configured to be divided into two parts and sent to the D port 10D via the valve 71. On the other hand, the pilot check valve 69 is connected to the piping 61 and the tank 33, and is opened by pilot pressure when the roller 8 is lowered in the illustrated state where the solenoid SOL ₇ is OFF or during crushing work. Port 10C is open to tank 33. Also, when touching metal, solenoid SOL ₇
When turned ON, the pilot check valve 69 closes and the connection with the tank 33 is cut off. Additionally, a remotely operated variable throttle valve 72 is interposed between the pilot check valve 69 and the tank 33, and when the roller 8 is lowered from the raised position, this throttle valve is throttled to complete the lowering. When the crushing operation begins, the cylinder is fully opened and the D port 10D of the cylinder 10 is brought to tank pressure.

With the above configuration, during crushing work, that is, when the roller 8 is lowered onto the table 5, the solenoid SOL ₇ is turned OFF.
(state shown), the pilot check valve 68 is closed, pressure oil is stored in the accumulator 34, and pressure oil is held in the pipes 21, 20 and the C port 10C side of the hydraulic cylinder 10. . On the other hand, the pilot check valve 69
is open and D port 10D is released to tank 33. If a metal touch occurs on one of the four rollers 8 during this crushing operation, the sensor detects this and issues a signal, and only the solenoid SOL ₇ corresponding to that roller 8 turns on, causing the pilot to Check valve 68 opens and rod check valve 69 closes. Therefore, the pressure oil in the accumulator 34, which had been held on the C port 10C side, is transferred to the pipes 70, 61 and the check valve 6.
8 and 71, and is also sent to D port 10D.
That is, the pressure oil in the accumulator 34 is divided into two at the same pressure to both ports 10C and 10D. In this case, as in the previous embodiment, the piston rod 11 moves toward the rod end due to the difference in pressure receiving area within the hydraulic cylinder 10, and only the roller 8 causing the metal touch is lifted. During this time, the other rollers 8 are lowered and the crushing operation continues. When the metal touch is soon resolved and a signal is issued, the solenoid SOL is turned OFF, the pilot check valve 68 is closed, and the pilot check valve 69 is opened, so that the D port 10D is released to the tank 33 and the pressure is released to the C port 10C side. Oil is replenished. Therefore, the roller 8, which had been lifted, descends.
It joins the other rollers 8 and continues the crushing work. By providing a short circuit to the cylinder 10 of each roller 8 in this way, there is no need to lift other rollers 8 that do not cause metal touch, and the crushing operation can be continued, so there is no need to interrupt the crushing operation. This can also prevent an extreme drop in grinding efficiency.
Solenoid when interrupting or finishing the grinding operation
SOL ₇ turns ON and pilot check valve 69
is closed, the pressure oil sent to the pipe 22 by the switching of the electromagnetic switching valve 23 passes through the pipe 61 to D.
It is sent to port 10D. At this time, since the check valve 71 is operating, the pressure oil is flowing to the C port 10C.
I never go to By supplying oil to the D port 10D, the four rollers 8 are lifted up. In addition, during each of the above operations, the electromagnetic switching valve 4
The operations of 5, 50, etc. are the same as in the embodiment shown in FIG. 1, so the explanation thereof will be omitted.

Although each of the above embodiments describes a hydraulic circuit for a crusher provided with four rollers, the number of rollers is not limited to this, and the present invention can be applied to a crusher having any number of rollers. It is something that

〔Effect of the invention〕

As is clear from the above description, according to the vertical crusher according to the present invention, the oil supply path of the hydraulic cylinder for the upper and lower crushing rollers is switched from the switching valve to the rod end side and the head end side to the accumulator on the rod end side. A bypass is used to short-circuit the pipe line heading towards the head end side port and the pipe line heading towards the head end side port, and this bypass is normally shut off, and the bypass is activated by a signal generated by a sensor that indicates the grinding roller is approaching the rotary table abnormally. Since a communicating switching valve device is provided, the pressure oil sent to the rod end side from the accumulator located near the hydraulic cylinder in the event of an abnormal approach is divided into two parts and sent to the rod end side and the head end side. This allows the piston rod to instantly move to the head end and lift the crushing roller off the rotary table by skillfully utilizing the pressure difference due to the difference in pressure receiving area between the rod end and head end of the cylinder. As a result, it is possible to prevent damage to the crushing roller ties and rotary table liner caused by metal touch.
It has various excellent effects such as improving its durability. Further, according to the present invention, as described above, when the grinding roller approaches abnormally, the grinding roller can be lifted instantly, and the grinding work can be restarted in a very short time after the metal touch is resolved, so that the vibration of the grinder can be reduced.
This has the advantage of eliminating noise generation in a short time and improving the working environment.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a vertical crusher, and FIGS. 2 and 3 show an embodiment of the vertical crusher according to the present invention,
FIG. 2 is a hydraulic circuit diagram thereof, and FIG. 3 is a hydraulic circuit diagram showing another embodiment of the present invention. 1...Vertical crusher, 5...Rotary table, 8...
...Roller, 10...Hydraulic cylinder, 10C...Rod end side port, 10D...Head end side port, 21, 22...Piping, 23...Solenoid switching valve, 34...Accumulator, 51...Bypass, 52... Pilot check valve, 53...Check valve, 54...Solenoid switching valve, 63...Switching valve device, 65...Solenoid switching valve, 68, 69...Pilot check valve, 71...Check valve.

Claims (1)

[Claims] 1 Equipped with a hydraulic cylinder that brings the crushing roller into contact with the rotary table by sending pressure oil to the rod end side via an accumulator, and separates the crushing roller from the rotary table surface by feeding pressure oil to the head end side. In the vertical crusher, both pipes from the switching valve of the oil feed route to the accumulator and the head end port of the hydraulic cylinder are short-circuited by a bypass, and this bypass is normally shut off, and the crusher A vertical crusher characterized in that a switching valve device is provided which operates in response to a signal of abnormal approach of a roller to a rotary table and connects the bypass.