JPH0617081Y2 - Flow sensor - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a flow sensor which is disposed in a flow path of a lubricating device and detects whether or not a lubricating oil is flowing.

[Conventional technology]

For example, a lubrication pipe is provided in the sliding portion of various devices to supply the lubrication oil. However, if the lubrication pipe is damaged or clogged, the lubrication oil supply is hindered and expensive. The bearings and rolls will burn out. Therefore, a flow sensor is arranged at the end of the oil supply pipe to constantly monitor whether or not the lubricant is actually supplied.

What is shown in FIG. 7 is an example of a flow sensor used for such an application.

As shown in the figure, a conventional flow sensor has a casing a in which a protrusion b is formed on the inner peripheral surface of one end side 1 over the entire circumference in the circumferential direction.
A through-hole c is formed, and a detected body d capable of reciprocating within the through-hole c for a predetermined distance and contacting the end of the protrusion b is provided inside the through-hole c. And
The detected body d holds the magnet e and positions the small diameter portion f formed on the one end side 1 in the narrow space g surrounded by the protrusion b, and further on the other end side m of the through hole c. The detected body d is biased toward the projecting portion b by a spring i interposed between the spring receiving member h fitted and fixed. Further, a magnetic detector j such as a reed switch or a hall element is arranged in parallel at a position adjacent to the through hole c in the casing a so that the movement of the detected object d can be detected. .

In the flow sensor having such a configuration, the lubricating oil is on one end side l.
It flows in from the right side in the drawing and goes from the right side to the left side in the drawing through the clearance k formed between the small-diameter portion f of the detection object d and the narrow space g in the through hole c. If the inflow occurs, the detected body d moves to the other end side m (left side in the figure) against the urging force of the spring i, and if the inflow of lubricating oil ceases, the detected body d urges the spring i. Is moved to one end side 1 (right side in the drawing) by detecting the movement by the magnetic detector j to detect the flow of the lubricating oil.

[Problems to be solved by the device]

However, since the viscosity of the lubricating oil changes depending on the temperature, even if the same oil is used, the movement of the detected object d may be insufficient depending on the operating temperature conditions. For example, even if the magnetic detector j is normally turned on and off in the normal temperature range (0 ° C to 50 ° C), the viscosity of the lubricating oil is lowered and the fluidity is deteriorated in the high temperature range (60 ° C to 100 ° C). As a result, the lubricating oil quickly passes through the clearance k in the clearance k designed to be used in the normal temperature range and the leak amount increases, so that the lubricating oil slightly moves the detected object d. However, the entire amount of the lubricating oil that has flowed in will pass through, and the magnetic detector j will be turned on and off.
There arises a problem that the operation cannot be performed normally.

In the conventional flow sensor, the clearance k
There is a problem that the relationship between the size and the spring pressure is extremely delicate, and it takes a lot of time and effort to set the optimum value.
Therefore, there is a problem that it is difficult to appropriately set the delivery amount of the lubricating oil.

The present invention has been made in view of the current situation, and a flow sensor that can reliably turn the magnetic detector on and off without being influenced by changes in operating temperature conditions and that can easily set the delivery amount is provided. It is intended to be provided.

[Means for solving the problem]

The flow sensor of the present invention that solves such problems is
One end face in the piston fitting hole 2c opened along the length direction
A cylinder fitting 2 having a piston 3 having a pressure receiving surface 3a and a small diameter portion 2b formed on the outer periphery is inserted and fixed in the through hole 1a, and the through hole 1a is penetrated from the other end 1c. Hole 1a
A magnet 6 having a smaller diameter and a spring 5 for urging the magnet 6 toward one end are sequentially inserted to press the piston 3 with the magnet 6, and the cylinder fitting 2
The space 4 formed between the outer surface of the small diameter portion 2b and the inner peripheral surface of the through hole 1a is in a state where the space 4 is always in communication with the other end side 1c, and when the piston 3 slides a certain distance X, The cylinder fitting 2 is characterized in that a communication passage 2d for communicating the space inside the fitting hole 2c with the space 4 is opened.

[Action]

The operation of the flow sensor having such a configuration is as follows.

When there is no supply of lubricating oil from the distribution valve, etc., the piston 3
Is pressed by the spring 5 through the magnet 6 toward the one end side 1b of the through hole 1a to completely close the communication path 2d, and the communication between the one end side 1b and the other end side 1c in the through hole 1a is complete. Has been cut off.

Next, when the lubricating oil is supplied from the distribution valve, the lubricating oil presses the one end surface 3a of the piston 3 which is the pressure receiving surface, and the spring 5
The piston 3 is moved toward the other end side 1c against the biasing force of. When the piston 3 moves a predetermined distance X toward the other end side 1c, the communication passage 2d opens and a predetermined amount of lubricating oil flows out toward the other end side 1c. Since the piston 3 is closely fitted in the piston fitting hole 2c, the one end surface 3a, which is the pressure receiving surface, has the communication passage 2d.
Is surely continued to be pressed toward the other end side 1c until is opened.

Then, when the supply of the lubricating oil from the distribution valve is stopped, the piston 3 moves toward the one end side 1b due to the restoring force of the spring 5, closes the communication passage 2d in the process of movement, and then returns to the origin. The reciprocating motion of the magnet 6 that moves together with the piston 3 is detected by the magnetic detection means to monitor the supply state of the lubricating oil.

〔Example〕

Next, the details of the present invention will be described based on the illustrated embodiment.
FIG. 1 is a sectional view of an embodiment of a flow sensor according to the present invention. This flow sensor has a through hole 1a formed in the casing 1 so as to penetrate the casing 1 in the longitudinal direction,
Inside the through hole 1a, a magnet 6 to be detected and a mechanism for moving the magnet 6 according to the movement of the lubricating oil are installed, and a lead is provided inside the sensor holding hole 7 provided adjacent to the through hole 1a. The switch 8 is housed and the sensor 9
Is placed close to the existing position of the magnet 6 after moving, the movement of the magnet 6 is turned on / off
The basic action is to detect as an action.

As the means for detecting the movement of the magnet 6, it is possible to use any other means as long as it is a magnetic detection means, for example, a Hall element or the like.

A female screw 1 is provided on one end 1b of the through hole 1a on the lubricating oil inflow side and on the other end 1c of the through hole 1a on the lubricating oil outflow side.
0 and 11 are screwed, and a joint (not shown) is connected to each. A protruding wall 12 is formed in a substantially central portion of the through hole 1a over a predetermined length, and a cylinder fitting in which a piston 3 whose one end surface 3a is a pressure receiving surface is fitted is inserted on one end side 1b from the protruding wall 12. 2 is fixed internally. As shown in FIG. 2, the cylinder fitting 2 includes a large diameter portion 2a having an outer diameter capable of being tightly fitted to the inner wall of the through hole 1a and a small diameter portion 2b having an outer diameter slightly smaller than that of the large diameter portion 2a. The end of the small diameter part 2b
The space 4 serving as a flow path for lubricating oil is formed between the outer peripheral surface of the small diameter portion 2b and the inner peripheral surface of the through hole 1a by being installed in the through hole 1a in a state of being brought into contact with the starting end portion of the through hole 1a. . Further, an O-ring for sealing is fitted in the annular groove formed along the outer circumference of the large diameter portion 2a to prevent leakage of lubricating oil between the outer surface of the large diameter portion 2a and the inner surface of the through hole 1a. A piston fitting hole 2c whose one end is made larger than the piston diameter is formed at the radial center of the through hole 1a, and at the center of the length of the cylinder fitting 2 from the outer peripheral surface of the small diameter portion 2b to the piston fitting hole 2c. The communication passage 2d that reaches is penetrated. Further, the piston fitting hole 2c is formed on the outer periphery of the end of the small diameter portion 2b.
A delivery hole 13 that reaches to the other side is formed, and a delivery path 14 that delivers the lubricating oil fed through the space 4 to the other end side 1c is formed. In the example shown in the figure, the communication passage 2d and the delivery hole 13 are provided at two positions above and below the through hole 1a, respectively, but the numbers thereof are appropriately set as necessary.

Reference numeral 6 in the figure denotes a magnet installed in a portion of the through hole 1a where the protruding wall 12 is formed. The magnet 6 is a through hole 1a.
The outer diameter is a through hole to form a lubricating oil flow path between
It is set smaller than the inner diameter of 1a, and the one end surface is pressed by the spring 5 so that the other end surface moves the piston 3 to the one end side.
It is configured to press toward 1b. Also, in the figure
Reference numeral 15 is a support for fixing one end of the spring 5.

The flow sensor of the present invention has the above-mentioned configuration, and its operation mode is as follows.

When there is no supply of lubricating oil from the distribution valve, Fig. 3 (a)
As shown in FIG. 3, the magnet 6 is used for the sensing unit 9 of the reed switch.
Exists at a position away from the sensor 9 and turns off the sensing unit 9, while
When the lubricating oil is supplied, as shown in FIG. 3B, the magnet 6 is present in the vicinity of the sensing unit 9 and turns on the sensing unit 9. The function of the cylinder fitting 2 is to supply the lubricating oil from the inflow side to the outflow side while prescribing the longitudinal movement of the magnet 6.

As shown in FIG. 4, the communication passage 2d is formed at a position away from the end of the cylinder fitting 2 by a distance X, and the one-shot lubricating oil delivery amount is determined by the distance X and the inner diameter D of the piston fitting hole 2c. It Therefore, as shown in FIG. 5, the inner diameter of the piston fitting hole 2c can be changed by changing the inner diameter of the piston fitting hole 2c so that the outer diameter of the piston 3 corresponds to the inner diameter of the piston fitting hole 2c. For example, the amount of lubricating oil delivered can be controlled.

FIG. 6 is an explanatory view showing the operating state of the cylinder fitting 2. The process from FIG. 6 (a) to FIG. 6 (b) shows the flow of the lubricating oil in the advance process of the piston 3, and FIG. The process from (b) to FIG. 6 (c) shows the retracting process of the piston 3. In the forward movement process of the piston 3, the lubricating oil presses the one end surface 3a of the piston 3 stopped at the origin position (Fig. 6 (a)), and the piston 3 is moved to the left side in the drawing until the communication passage 2d is opened. To move. Since the piston 3 is tightly fitted in the piston fitting hole 2c, the movement of the piston 3 is surely performed until the communication passage 2d is opened even when the viscosity of the lubricating oil is low.

When the communication passage 2d is opened (FIG. 6 (b)), the lubricating oil flowing in the piston fitting hole 2c is formed in the cylinder fitting 2 after flowing out to the space 4 through the communication passage 2d. Outflow path
It is sent to the magnet 6 side via 14. In this state, the magnet 6 continues to press the spring with a strong force against the restoring force of the spring 5, and this state is maintained until the delivery of a predetermined amount of lubricating oil is completed.

When the delivery of the specified amount of lubricating oil is completed, the piston fitting hole 2c
The internal pressure in the inside greatly decreases, and the moving direction of the piston 3 is reversed. Then, at this stage, the supply of the lubricating oil from the distribution valve is also stopped. In this way, in the forward stroke, the communication passage
Since the internal pressure in the piston fitting hole 2c is kept high until 2d is opened, the piston 3 can be reliably moved by the predetermined distance X even when the lubricating oil of which the viscosity is lowered is targeted. it can.

Next, the retracting process of the piston 3 is started, the piston 3 is pressed to the left side in the drawing by the restoring force of the spring 5, and the lubricating oil remaining in the piston fitting hole 2c is discharged to the outside of the cylinder fitting 2 to return to the origin ( Fig. 6 (c)).

As described above, in the flow sensor of the present invention, since the piston 3 is closely fitted in the piston fitting hole 2c, the communication passage
The lubricating oil flowing in the piston fitting hole 2c does not leak until 2d is opened, and the internal pressure in the piston fitting hole 2c can be maintained in a high state. Therefore, the piston 3 can be reliably moved by the predetermined distance X regardless of the viscosity of the lubricating oil, and the predetermined amount of lubricating oil can be reliably delivered and the lubricating oil can be delivered by the ON / OFF operation of the sensing unit 9. It is possible to reliably monitor the state.

Further, since the inner diameter of the piston fitting hole 2c can be designed relatively freely, it is possible to adjust the delivery amount of the lubricating oil by appropriately designing the inner diameter of the piston fitting hole 2c. Further, since the control of the delivery amount can be performed only by replacing the cylinder fitting 2, it is possible to obtain flow sensors of various delivery amounts while using common parts other than the cylinder fitting 2. It can also contribute to the price reduction of the sensor.

[Effect of device]

The flow sensor of the present invention is configured as described above, and in particular, the piston 3 is closely fitted in the piston fitting hole 2c, and the communication passage 2d that is opened when the piston 3 moves the distance X is provided. Since the lubricating oil is delivered to the outside of the flow sensor through the passage 2d, the lubricating oil flowing in the piston fitting hole 2c does not leak until the communication passage 2d is opened, and the inside of the piston fitting hole 2c does not leak. The internal pressure can also be kept high. Therefore, even when the viscosity of the lubricating oil is low, such as when the lubricating oil is used in a high temperature environment, the piston 3 can be reliably moved by the predetermined distance X, and a predetermined amount of the lubricating oil can be reliably delivered. It is possible to reliably monitor the delivery state of the lubricating oil by the ON-OFF operation of the sensing unit 9.

Further, by appropriately designing the inner diameter of the piston fitting hole 2c, it is possible to adjust the delivery amount of the lubricating oil, and the delivery amount can be controlled only by replacing the cylinder fitting 2. Therefore, it is possible to obtain flow sensors with various delivery amounts while using common parts other than the cylinder fitting 2, and it is possible to reduce the cost of the flow sensor.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a flow sensor of the present invention, FIG. 2 is an enlarged perspective view of a cylinder fitting used in the same embodiment, and FIGS. 3 (a) and 3 (b) show the same embodiment. FIG. 4 is an explanatory view showing a moving state of the magnet, FIG. 4 is an enlarged explanatory view showing a main part of the same embodiment, FIG. 5 is another embodiment of the present invention, and FIGS. 6 (a), 6 (b) and 6 (c). ) Is an explanatory view showing a piston moving process in the embodiment, and FIG. 7 is a conventional example. 1a: through hole, 1b: one end side, 1c: other end side, 2: cylinder fitting, 2a: large diameter part, 2b: small diameter part, 2c: piston fitting hole, 2d: communicating passage, 2e: O-ring, 3 : Piston, 3a: One end surface, 4: Space, 5: Spring, 6: Magnet, 7: Sensor holding hole, 8: Reed switch, 9: Sensing part, 10, 11: Female screw, 12: Projection wall, 13: Outflow hole, 14: outflow passage, 15: support tool.

Claims (1)

[Scope of utility model registration request] 1. An object to be detected, which is made of a magnet or has a magnet, which is moved back and forth in accordance with the flow of lubricating oil flowing in the through hole, is provided inside the through hole provided in the casing, and The detection body is biased in one direction by a return spring, and a magnetic detection means such as a reed switch or a hall element is arranged adjacent to the through hole to detect the forward / backward movement of the magnet by the magnetic detection means. In the flow sensor that detects the flow of fluid by doing so, the piston (3) having the one end surface (3a) as the pressure receiving surface is fitted into the piston fitting hole (2c) opened along the length direction, Further, a cylinder fitting (2) having a small diameter portion (2b) formed on the outer periphery is inserted and fixed in the through hole (1a), and the other end side (1) of the through hole (1a) is fixed.
From c), a magnet (6) having a smaller diameter than the through hole (1a) and a spring (5) for urging the magnet (6) toward one end side are sequentially inserted, and the magnet (6) is used to insert the piston ( 3) While pressing the cylinder fitting (2), the space (4) formed between the outer surface of the small diameter portion (2b) of the cylinder fitting (2) and the inner peripheral surface of the through hole (1a) is connected to the other end side (1c). When the piston (3) slides for a certain distance X, and is not in the state of being in continuous communication,
A flow sensor characterized in that a communication passage (2d) for communicating the space inside the piston fitting hole (2c) and the space (4) is opened in the cylinder fitting (2).