JPH0342813U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram showing an embodiment of the pressure increasing device according to the present invention, Fig. 2 is a side view of a crusher which is an example of application of the present invention, and Fig. 3 is a pressure increasing device according to the present invention. FIG. 3 is a hydraulic circuit diagram showing another embodiment of the present invention.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a crusher having a structure in which the crusher arm is opened and closed by a hydraulic main cylinder and also has a pressure booster cylinder, the main cylinder is supplied with pressure oil when the crusher arm is closed. The main circuit between the first chamber and the control valve is provided with a pilot check valve that allows backflow when the crusher arm opens, and a circuit is branched from between the control valve and the pilot check valve of the main circuit. A sequence valve that opens when the oil pressure in the main circuit exceeds a set pressure is provided, and a switching valve is provided to connect the low pressure chamber of the pressure booster cylinder to the secondary circuit or oil tank side circuit of the sequence valve. , a circuit connects the high pressure chamber of the pressure booster cylinder and the first chamber, and a stroke end detector of the pressure booster cylinder is provided as a pilot means for the switching valve, and when the stroke end is detected by the detector, the pressure increases. A pressure booster characterized in that a low pressure chamber of a cylinder communicates with an oil tank, and pressure oil can be introduced into the low pressure chamber via the sequence valve when a stroke end is not detected. 2 As a pilot means for the switching valve, not only the stroke end detector of the pressure booster cylinder but also the hydraulic pressure of the secondary circuit of the sequence valve is used, and when the stroke end is detected by the detector, the low pressure chamber of the pressure booster cylinder is connected to the oil tank. communication, so that pressure oil can be introduced into the low pressure chamber through the sequence valve when the stroke end is not detected, and when the sequence valve is opened when the stroke end is not detected, pressure oil is introduced into the low pressure chamber through the casing valve. The pressure increasing device according to claim 1, characterized in that the pressure increasing device has a configuration in which: 3 A pilot circuit that connects the high pressure chamber of the pressure increase cylinder and the first chamber of the main cylinder is configured to allow backflow when the sequence valve is opened, and to supply high pressure oil from the pressure increase cylinder to the first chamber. A check valve is provided, and a check valve is provided between the second chamber of the main cylinder to which pressure oil is supplied during the opening operation of the crusher arm and the high pressure chamber of the pressure booster cylinder, and allows the pressure oil to flow into the high pressure chamber. 3. The pressure increase device according to claim 2, wherein the pressure increase device is connected through the pressure booster.