JPS6311556B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a two main pipe type central lubrication device, in detail:
A distribution valve is connected to a pair of main pipes serving as a discharge line or a return line, and a switching valve device is provided to alternately connect one of the main pipes to a pump line and the other main pipe to a tank line. This invention relates to an end type two main pipe type lubricating device.

(Prior Art) This type of lubricating device is described in, for example, Japanese Patent Publication No. 53-32469.

An outline of this type of lubricating device will be explained based on FIG. 3. In this device, a plurality of distribution valves 52 are connected to a pair of main pipes 50 and 51, and these main pipes 50 and 51 are connected to each other.
0,51, a pump line 53, and a tank line 54 are provided.
0 and 51 can be alternately switched to the discharge line and the return line.

Further, the distribution valve 52 is a normal one, and is provided with a valve body 56 having a plunger chamber 58 for metering.
A metering plunger 5 is provided in the plunger chamber 58.
7 is slidably installed inside the plunger chamber 58, and both sides of the plunger 57 in the sliding direction are used as measuring chambers 58a and 58b, respectively, and the main pipes 50 and 51 are connected to the valve body 56. Ports 59 and 60 and a greasing port 61 connected to a portion to be lubricated are formed. Furthermore, the valve body 56 has one of the metering chambers 58.
a or 58b and the connection ports 59, 60
Of these, a pilot piston 62 is installed internally to selectively connect the connection port 59 or 60 that communicates with the main pipe 50 or 51 on the discharge line side, and the greasing port 61 with the other metering chamber 58b or 58a. , and both ends of this piston 62 are communicated with each of the connection ports 59 and 60,
The piston 62 is configured to be switched by the difference in internal pressure between the main pipes 50 and 51.

Further, the switching valve device 55 includes each of the main pipes 5
It consists of two 3-port, 2-position electromagnetic switching valves 55a and 55b which selectively connect ports 0 and 51 to the pump line 53 and the tank line 54, respectively.

In addition, 63 is a pump, 64 is a motor, 65 is a relief valve connected to the pump line 53, and 66 is a tank for storing lubricating oil.

During greasing, for example, from the state shown in FIG. It communicates with line 53. Then, via the connection port 60 of the distribution valve 52, the piston 62
Pump pressure acts on the lower end side of FIG. 3, and the piston 62 switches as shown in FIG.
In addition, the other measuring chamber 58a and the greasing port 61 are connected to each other.

Thus, the metering plunger 57 moves in the direction of the arrow A in FIG. 4, and the other metering chamber 58a
The lubricating oil stored in the lubricating oil is discharged to the lubricated part through the greasing port 61, and at the same time, a predetermined amount of lubricating oil is stored in the one measuring chamber 58b. . Then, when the greasing from each distribution valve 52 is completed, the distribution valve 5
2 are all in the state shown in FIG. 4, and in this state, the pump 63 is stopped, and each of the solenoid valves 55
a, 55b are both de-energized, and each of the main pipes 5
0 and 51 are both kept in communication with the tank line 54 until the next time of refueling.

(Problems to be Solved by the Invention) By the way, when the central lubrication system is used in a place with high ambient temperature such as a steelworks, the above-mentioned central lubrication system is The lubricating oil in each of the main pipes 50, 51 of the device may be heated by the high temperature surrounding air, resulting in a rise in temperature and volumetric expansion.

When the device is stopped, each of the main pipes 5
0 and 51 are both connected to the tank line 54, so the lubricating oil that has expanded in volume flows out to the tank 66, but generally,
The pipelines from the distribution valve 52 connection positions a and b in each of the main pipes 50 and 51 to the tank 66 are long and have resistance, so the flow of the lubricating oil at this time causes the main pipes 50 to , 51, internal pressure is generated at the connection positions A and B, respectively.

At this time, an imbalance occurs in the internal pressures at the connection positions A and B of the distribution valve 52 in each of the main pipes 50 and 51, and the internal pressure at A of the main pipe 50 is higher than the internal pressure at B of the main pipe 51. When the pressure rises, this differential pressure acts on the piston 57 of the distribution valve 52, and the piston 57 is pushed down from the state shown in FIG. 4 as shown in FIG. 3.
The main pipe 50 communicates with one measuring chamber 58a, and the lubricating oil expanded in volume within the main pipe 50 flows into the measuring chamber 5.
8a, causing a malfunction in which the lubricating oil stored in the other measuring chamber 58b is discharged from the greasing port 61 to the lubricated part even though this device is stopped. It was hot.

Therefore, an object of the present invention is to provide each of the main pipes 50,
At connection positions a and b of the distribution valve 52 at 51, the internal pressure of the main pipe 50 or 51 on the side that was the discharge line at the end of greasing the device is always maintained at the other main pipe 51 or 51. 5
The piston 62 is maintained at an internal pressure of 0 or higher to prevent the piston 62 from performing a switching operation while the device is stopped, and the distribution valve 52 is maintained at an internal pressure of 0.
The purpose is to ensure that malfunctions can be prevented.

(Means for solving the problems) The configuration of the present invention will be explained based on FIG.
A distribution valve 3 is connected to a pair of main pipes 1 and 2 serving as a discharge line or a return line, and one main pipe 1 or 2 is connected to a pump line 4, and the other main pipe 2 or 1 is connected to a tank T. In a two-main type central lubrication system equipped with a switching valve device 6 that alternately switches and connects a tank line 5 to a tank line 5, a back pressure valve 14 is provided to set back pressure. Means is provided to connect the main pipe 1 or 2, which was a discharge line at the time of completion, to the tank T via the back pressure valve 14.

(Function) To explain the case where greasing is completed in the state shown in FIG. 1 and the device is stopped in this state, the ambient temperature of the device increases during this stop, and the main pipes 1 and 2 When the volume of lubricating oil inside increases due to temperature rise, back pressure is applied to the main pipe 1 or 2 on the side that was the discharge line at the end of lubrication by the back pressure valve 14, so that the distribution in the main pipe 1 or 2 is The internal pressure at the connection position of the valve 3 can always be maintained higher than the internal pressure at the same connection position in the other main pipe 2 or 1, and as a result, malfunction of the distribution valve 3 can be reliably prevented.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The one shown in Fig. 1 is an end-type two-main pipe central lubrication device, which is equipped with a pair of main pipes 1 and 2 that serve as a discharge line or a return line.
A plurality of distribution valves 3 are connected to one of the main pipes 1 or 2 and a pump line 4 connected to the pump P, and a tank line 5 is connected to the other main pipe 2 or 1 and the tank T. It is provided with a switching valve device 6 that alternately switches and connects. The switching valve device 6 will be described in detail later.
Further, in FIG. 1, R is a relief valve connected to the pump line 4, and G1 and G2 are pressure gauges, respectively.

Further, the distribution valve 3 is provided with a valve body 8 having a plunger chamber 7 for metering, and the plunger chamber 7
A metering plunger 9 is slidably installed inside the plunger chamber 7, and both sides of the plunger chamber 7 in the sliding direction of the plunger 9 are respectively metering chambers 7a and 7b. 2, and a greasing port 12 connected to the lubricated part. Further, the valve body 8 has one of the metering chambers 7a or 7b and one of the connection ports 10 and 11 that communicates with the main pipe 1 or 2 on the discharge line side, and the other one of the measurement chambers 7a or 7b. A pilot piston 13 for selectively connecting the metering chamber 7b or 7a and the greasing port 12 is installed inside.

Furthermore, both ends of the piston 13 are communicated with the connection ports 10 and 11, and the piston 13 is switched by the difference in internal pressure between the main pipes 1 and 2.

Thus, to explain the operation of this distribution valve 3, for example, from the state shown in FIG. When the return line is set as the return line, pump pressure acts on the left end surface of the pilot piston 13 in FIG. 1, and tank pressure acts on the right end surface, so that the piston 13 is at the right end position as shown in FIG. The switching operation is performed.

As a result, one of the metering chambers 7a is communicated with the main pipe 1 via the connection port 10, and the other metering chamber 7b is communicated with the greasing port 12. As a result, pump pressure acts on the left end face of the metering plunger 9, causing the plunger 9 to move to the right from the state shown in FIG. 2 as shown in FIG. Oil is supplied to each lubricated part from the greasing port 12.

The same applies when the main pipe 1 is used as a return line and the main pipe 2 is used as a discharge line.
Explanation will be omitted.

Therefore, in the two main pipe type central lubrication system configured as described above, a back pressure valve 14 is installed which connects the secondary side to the tank line 5 and sets the back pressure of the main pipe 1 or 2 when the operation is stopped. At the same time, when the switching valve device 6 is stopped due to the completion of greasing of the lubricating device, one of the main pipes 1 and 2, which was a discharge line at the end of the greasing, is connected to the switching valve device 6.
A means for opening the tank T to the tank T via the back pressure valve 14 is provided.

The switching valve device 6 having the above means will be described in detail below.

The switching valve device 6 is comprised of three-port, two-position electromagnetic switching valves 15 and 16, and a five-port, two-position pressure release valve 17.

Each of the electromagnetic switching valves 15, 16 has two first and second fixed ports 15a, 15b and one
6a, 16b and one switching port 15c, 16
c, and one of the first fixed ports 1
Each branch pipe 4 of the pump line 4 is connected to 5a and 16a.
a, 4b are connected, and primary side branch pipes 18a, 18b of a back pressure circuit 18 in which the back pressure valve 14 is interposed are connected to the other second fixed ports 15b, 16b. In addition, the switching ports 15c and 16
c are connected to fixed ports 17c and 17d, which will be described later, of the pressure release valve 17, respectively.

As described in detail later, during operation of this lubricating device, the electromagnetic switching valves 15, 16
By energizing one of the main pipes 1 or 2 corresponding to the solenoid valve 15 or 16 on the energized side.
communicates with the pump line 4 via the pressure release valve 17 and can be used as a discharge line, and when the lubricating device is stopped, both the electromagnetic switching valves 15 and 16 are de-energized. By doing so, the main pipe 1 or 2 on the side that was the discharge line at the end of greasing can be communicated with the back pressure circuit 18 via the pressure release valve 17 as well.

Further, the pressure release valve 17 is connected to the spool hole 19.
A switching spool 20 is installed inside the switch spool 20, and five ports opening into the spool hole 19 are formed. Specifically, first and second switching ports 17a and 17b connecting the main pipes 1 and 2 are connected to each other. and,
Each of the switching ports 1 of the electromagnetic switching valves 15 and 16
5c, 16c, and each port 15c, 16
first and second fixed ports 17c and 17d that apply a pressure of c to both end surfaces of the spool 20, and a third fixed port 17e that connects the tank line 4.
and is formed. Moreover, when the switching spool 20 is at the right end switching position in FIG.
The fixed port 17c is also the second switching port 1.
7b and the third fixed port 17e are connected, and when the piston 20 is in the left end side switching position, the first switching port 17a and the third fixed port 17e are also connected to each other. The second switching port 17b and the second fixed port 17d are communicated with each other.

Therefore, as mentioned above, this pressure release valve 17
Accordingly, the electromagnetic switching valve 15 or 16 on the energized side
The main pipe 1 or 2 on the side corresponding to the switching valve 1
5 or 16, the main pipe 1 or 2 can be used as a discharge line, and in particular, the other main pipe 2 or 1 can be connected to the back pressure valve 14 as a return line, as will be explained later. This allows direct connection to the tank line 5 without going through.

Hereinafter, the operation of the present lubricating device will be explained focusing on the switching operation of the switching valve device 6.

The case where the greasing operation is started from the state where the distribution valve 3 is stopped in the state shown in FIG. 2 will be explained.
(At this time, although not shown, the spool 20 of the pressure release valve 17 is located at the left end switching position.) () Start the pump P and switch one of the electromagnetic switching valves. 15 is energized, and the other electromagnetic switching valve 16 is de-energized. Thus, () the switching port 15c of the switching valve 15 and the first
The fixed port 15a communicates with the first fixed port 17c of the pressure release valve 17 and the pump line 4. In addition, in the other switching valve 16, the switching port 16c and the second fixed port 16b are connected, so the second switching port 17b of the pressure release valve 17 and the back pressure circuit 18 are communicated with each other. Ru. Therefore, () the pump pressure of the pump P and the back pressure set by the back pressure valve 14 act on both ends of the piston 20 of the pressure release valve 17, respectively. Since the back pressure is set considerably lower than the pump pressure, the piston 20
The switch is operated to the right end switching position in the figure. As a result, the first switching port 17a and the first fixed port 17c communicate with each other, one of the main pipes 1 communicates with the pump line 4 via the switching valve 15, and the second switching port 17b communicates with the third fixed port 17a. The other main pipe 2 is directly connected to the tank line 5 in communication with the fixed port 17e. Thus, one of the main pipes 1 serves as a discharge line, and the other main pipe 2 serves as a return line. As a result, () each distribution valve 3 connected to each of the main pipes 1 and 2;
Pump pressure acts on each first connection port 10, and the second connection port 11 is opened to the tank T. Therefore, as described above, the piston 13 of the distribution valve 3 is switched to the right end switching position as shown in FIG. Pump pressure acts on the plunger 9 to move the plunger 9 to the right, and the lubricating oil stored in one of the metering chambers 7b is supplied to each lubricated portion through the greasing port 12. () When the greasing operation of all the distribution valves 3 is completed, the internal pressure of one of the main pipes 1 increases. Then, a pressure detector (not shown) provided at the end of the main pipe 1 detects this high pressure and de-energizes the electromagnetic switching valve 15 and commands the pump P to stop. . Then, () in the electromagnetic switching valve 15, the switching port 15c is connected to the second fixed port 15b,
the first fixed port 17 of the pressure relief valve 17;
c is connected to the back pressure circuit 18 via the switching valve 15.
connected to.

At this time, the right end surface of the piston 20 of the pressure release valve 17 remains connected to the back pressure circuit 18 via the other switching valve 16, so the piston 20 does not operate at all. Therefore, during this stoppage, the main pipe 1, which was a discharge line, is connected to the back pressure circuit 18 via one of the switching valves 15, while the other main pipe 2 is connected to the back pressure circuit 18, as during operation. tank line 5
It is directly connected to.

In the above state (the state shown in FIG. 1), the lubricating device continues to be stopped until the next time of lubricating. During this stoppage, since the ambient temperature of the lubricating device is high, the temperature of the lubricating oil remaining in each of the main pipes 1 and 2 may rise and the volume may expand. In this case, a lubricating oil flow occurs in which the lubricating oil in each main pipe 1, 2 flows out into the tank T due to the volumetric expansion. Furthermore, due to this flow, internal pressure is generated at connection positions a and b of each distribution valve 3 in each of the main pipes 1 and 2, respectively, due to pipe resistance downstream from the positions.

() In this case, as mentioned above in (),
The main pipe 1, which was a discharge line during greasing, is opened to the tank line 5 via the back pressure circuit 18 during this stop, and the other main pipe 2, which was a return line, is connected to the tank line 5 even during the stop. Since the pressures at the connection positions A and B in the main pipes 1 and 2 are compared, the pressure at the point A in the main pipe 1 is higher than the pressure at the point B in the main pipe 2. In contrast, the set pressure of the back pressure valve 14 is always maintained high. That is, at connection positions A and B of each distribution valve 3 of each main pipe 1 and 2, the internal pressure of the main pipe 1 on the side that was the discharge line when the lubricating device was stopped is always maintained higher than the internal pressure of the other main pipe 2. It can be done. On the other hand, () Since the main pipe 1 was a discharge line at the end of greasing, the piston 13 of the distribution valve 3
is located at the right end switching position as shown in FIG.
Since a higher pressure acts on the left end surface of the piston 13 than on the right end surface, the piston 13
There is no movement at all from the end side switching position.

Therefore, even if the lubricating oil in the main pipes 1 and 2 expands in volume due to a rise in temperature while the lubricating device is stopped, the distribution valve 3 will not be inadvertently operated to supply the lubricating oil.

Note that the case where the other electromagnetic switching valve 16 of the switching valve device 6 is energized and the one electromagnetic switching valve 15 is de-energized to carry out greasing operation is also the same as the above case, so the explanation will be omitted. do.

Although the switching valve device 6 of the above embodiment uses two electromagnetic switching valves 15 and 16, for example, if it is a 4-port 3-position switching valve, only one electromagnetic switching valve is sufficient. It is not limited.

In this embodiment, a detection rod 91 is provided on one side of the plunger 9 in the distribution valve 3.
At the same time, the opening of the plunger chamber 7 on the rod 91 side is closed by a lid 71, and the lid 71 has a sliding hole 72 for slidingly guiding the rod 91, and a sliding hole 72 for slidingly guiding the rod 91. A detection window 73 is formed for visually confirming the movement of the plunger 9 from the outside, and a limit switch 74 is provided which is operated by the rod 91 when the plunger 9 is located at the left end switching position. By doing this, it is possible to visually check from the outside whether each distribution valve 3 is operating normally, and the operation check of the distribution valve 3 can be automated based on the output of the limit switch 74. I'm also trying to do that.

(Effects of the Invention) As described above, the present invention connects the distribution valve 3 to the pair of main pipes 1 and 2 that serve as the discharge line or the return line, and also connects one of the main pipes 1 or 2 to the pump line 4. , a back pressure valve 14 that sets the back pressure in a two-main pipe central lubrication system provided with a switching valve device 6 that alternately switches and connects the other main pipe 2 or 1 and the tank line 5 connected to the tank T. When stopping due to the end of greasing, the main pipe 1 or 2 which was the discharge line at the end of greasing
Since a means is provided for communicating this with the tank T via the back pressure valve 14, even if the lubricating oil in each of the main pipes 1 and 2 expands due to a temperature rise when greasing is stopped, the distributing valve due to this This makes it possible to reliably prevent the malfunction described in step 3.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram of the embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the distribution valve of the same embodiment, Fig. 3 is a hydraulic circuit diagram of the prior art, and Fig. 4 is the distributing valve of the prior art. FIG. 1... Main pipe, 2... Main pipe, 3... Distribution valve, 4...
...Pump line, 5...Tank line, 6...Switching valve device, 14...Back pressure valve, P...Pump, T...
…tank.

Claims (1)

[Claims] 1. A distribution valve 3 is connected to a pair of main pipes 1 and 2 serving as a discharge line or a return line, and one of the main pipes 1 or 2 is connected to a pump line 4,
In a two-main pipe type central lubrication system provided with a switching valve device 6 that alternately switches and connects the other main pipe 2 or 1 and the tank line 5 connected to the tank T, a back pressure valve 14 for setting the back pressure is provided. and a means for communicating the main pipe 1 or 2, which was a discharge line at the end of the greasing, to the tank T via the back pressure valve 14 when the main pipe is stopped due to the end of greasing. Centralized lubrication device.