JPH056203U - Oil leakage prevention mechanism of hydraulic cylinder device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Completely prevent oil leakage from the cylinder device by collecting oil leakage that could not be prevented by the oil seal. [Structure] A pair of oil seals 15 and 16 is provided on a sliding surface of a cylinder cylinder 4 with respect to a rod 3, and an oil sump groove 17 is provided between the oil seals 15 and 16, and an interval is provided in the axial direction. A flexible tube 18 as an oil collecting means is connected to the oil collecting groove 17 while keeping the circumference.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil leakage prevention mechanism in a hydraulic cylinder device in which a cylinder cylinder and a rod are coaxially arranged and can be slid relative to each other in an axial direction.

[0002]

[Prior Art]

 In the hydraulic cylinder device, for example, when a vehicle maintenance lift is taken as an example, an inverted type in which a rod is fixed in an upright posture and a cylinder cylinder to which a carriage is attached is moved up and down is structurally advantageous. In this case, the operating oil is fed through an oil passage provided in the rod, and the conventional cylinder device has a cylinder cylinder 4 having a sliding surface with respect to the rod 3 as shown in FIG. An oil seal 15 that prevents only leakage and an oil seal 16 that also functions as a dust seal that prevents foreign matter from entering from the outside are provided.

[0003]

[Problems to be solved by the device]

 In order to improve the oil leakage prevention function of the oil seal, there are countermeasures such as mirror-finishing the sliding surface of the rod and using a dust seal with good performance, but it is not possible to completely eliminate the leakage. It is technically impossible, and if used, sooner or later the performance of the oil seal itself will deteriorate, so oil leakage is inevitable. Therefore, there were problems such as dust and dirt adhering to the leaked oil, causing troubles on sliding parts, soiling the surrounding area and the floor, and causing oil shortage.

[0004]

[Means for Solving the Problems]

 If the oil seal cannot completely prevent the oil leak, at least some measures must be taken to prevent the oil from leaking to the outside. Therefore, a pair of oil seals are formed on the sliding surface of the cylinder on the rod cylinder, and oil sump grooves are circumferentially provided between the oil seals and the oil seals with a space in the axial direction. We have devised an oil leak prevention mechanism that connects oil recovery means to the.

[0005]

[Action]

 Leakage oil that could not be blocked by the inner oil seal is collected in the oil sump groove, and the oil collected there is collected by the oil collection means, so there is no oil leakage and the oil seal seal performance is slightly reduced. Even if it drops, it will be covered.

[0006]

【Example】

 The oil leakage prevention mechanism according to the present invention will be described by taking a ram cylinder used in a vehicle maintenance lift as an example. Reference numeral 1 denotes a cylinder device that is erected on a movable carriage 2, and is a so-called inverted type ram cylinder in which a cylinder tube 4 is assembled so that a lower end thereof is covered with a fixed rod (ram rod) 3. An oil passage 5 is formed in the center of the rod 3, the upper end of the oil passage 5 opens into the cylinder cylinder 4, and the lower end of the oil passage 8 is supplied with hydraulic oil from an oil tank 7 via a hydraulic unit 6. Are connected. The lower end of the cylinder cylinder 4 is closed by a rod guide 4a having a rod insertion hole at the center, and is kept in sliding contact with the rod 3 through the rod insertion hole of the rod guide 4a.

An air-bleeding bolt 9 is provided on the upper end of the cylinder cylinder 4 to appropriately remove unnecessary air from the cylinder chamber. Further, a brim-shaped support ring 10 having a curved upper surface is fixed to the outer periphery, and a carriage 11 is inserted into the support ring 10 and a cylinder tube 4 is inserted into a mounting hole 12 formed at the base end thereof. It is stopped and supported by a detent 13. The carriage 11 is guided in the vertical direction by a carriage guide 11a provided so as to surround the cylinder device on the carriage 2.

A wear ring 14, an oil seal 15, and an oil seal 16 also serving as a dust seal are sequentially attached to the rod guide 4 a from above from above, with a space between the oil seal 15 and the oil seal 16. An oil sump groove 17 is provided around. A port 17a communicating with the outside is formed in the oil sump groove 17, and a flexible tube 18 communicating with the oil tank 7 is connected to the port 17a. A rotatable swivel elbow 18a is used at the connecting portion with the flexible tube 18, and a guide member 19 is provided in the middle of the flexible tube 18 to provide directionality to prevent damage.

In the cylinder device 1 thus formed, the working oil supplied from the hydraulic unit 6 flows into the cylinder chamber from the upper end through the pressure oil pipe 8 and the oil passage 5 in the rod 3, 4, the carriage 11 is raised. When the pressure oil is released, the cylinder cylinder 4 descends due to its own weight, and the carriage 11 also descends. The hydraulic oil in the cylinder cylinder 4 that could not be blocked by the oil seal 15 flows into the oil sump groove 17. Since the oil sump groove 17 goes around the rod once, all the leaked oil is accumulated in the oil sump groove 17. Since the pressure in the oil sump groove 17 is almost the same as the atmospheric pressure, the airtightness is kept high by the oil seal 16 and there is no risk of leaking to the outside, and the leaked oil flows out of the oil sump groove 17 to the port. Then, the oil is collected in the oil tank 7 via the flexible tube 18.

As a result, the hydraulic oil does not leak to the outside of the cylinder device, the device and the surroundings of the device are not polluted, the oil shortage does not occur, and the creme from the user is reduced. In addition, the vehicle maintenance lift does not have a safety problem because it is equipped with descent prevention means to prevent natural descent in the event of an oil leak, but the surface of the rod exposed to the outside is not affected. However, if dust or dirt easily adheres due to oil leakage, it may cause foreign matter to enter the cylinder. However, since there is no risk of oil leakage, the life of the seal portion is extended.

Although the ram cylinder in the vehicle maintenance lift has been described in the embodiment, the application and type are not limited as long as the cylinder device allows the rod and the cylinder tube to slide relative to each other. Further, the oil recovery means does not rely on natural recovery, and for example, a forced recovery means for periodically sucking up with a pump can be adopted.

[0012]

[Effect of the device]

 According to the present invention, since the oil leakage from the cylinder device can be completely prevented, the device and the floor will not be contaminated, and all the oil accumulated in the oil sump groove will be collected in the tank, so there will be no oil shortage. Do not wake up.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an oil leakage prevention mechanism of a hydraulic cylinder device according to the present invention.

FIG. 2 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1 ... Cylinder device, 2 ... Cart, 3 ... Rod, 4 ...
・ Cylinder cylinder, 4a ・ ・ Rod guide, 5 ・ ・ Oil passage, 6
..Hydraulic unit, 7 ... Oil tank, 8 ... Pressure oil pipe, 9 ... Air bleeding bolt, 10 ... Support ring, 11 ... Carriage, 11a ... Carriage guide, 12 ... Mounting hole, 13 ..Rotation stop, 14 ...
Wear ring, 15, 16 ... Oil seal, 17 ...
Oil sump groove, 17a ... port, 18 ... guide member, 1
9 ... Flexible tube.

Claims (1)

[Claims for utility model registration] Claims: 1. A hydraulic cylinder device in which a cylinder cylinder and a rod are coaxially arranged and slidable relative to each other in the axial direction. A hydraulic cylinder in which a pair of oil seals are provided on the sliding surface, and oil sump grooves are circumferentially provided between the oil seals and the oil seals with an axial interval therebetween, and oil collecting means is connected to the oil sump grooves. Device oil leakage prevention mechanism.