TYPES OF HYDRAULIC CYLINDERS


BLOCK CYLINDER (BZ)

A characteristic feature of block cylinders is their rectangular housing. This housing shape allows the imple- mentation of various mounting options. They can be operated with an operating pressure of up to 500 bar (7250 PSI), and there are various options for sensing the piston position. For strokes greater than 200 mm (7 .87 inches) the housing has a cuboid shape; larger strokes are implemented using a tube between the cuboid head and the bottom. The main area of application of block cylinders is mold construction. 

 

 


BLOCK CYLINDER WITH WEDGE CLAMP ELEMENT / GUIDE ROD (BZK/BZF)

With these cylinders, a guide housing is flanged to a block cylinder. This housing guides a hardened rod that can be loaded with side forces. With the wedge clamp element (BZK), a bevel is created in the guide rod. This can be used, for example, to for the clamping of workpieces. With the BZF, the guide rod is used as a guide with the capability to absorb side forces, which with hydraulic cylinders normally has to be avoided.

 

 


BLOCK CYLINDER WITH NON ROTATING PISTON ROD (BVZ)

These cylinders are available up to 250 bar (3625 PSI) and maximum permissible torques between 3 and 90 Nm (2 .21 and 66 .38 foot-pound force). This cylinder option is always advantageous when the piston rod – and any tools that it moves – are not allowed to rotate.

 

 

 


CIRCULAR BLOCK CYLINDER (RZ)

Circular block cylinders are a variant of the block cylinder product line. Their structural design is the same as  that of the block cylinder . Their externally visible difference from them is their cylindrical housing, which has proven to be advantageous in some installation situations where little space is available.

 

 

 


FLANGED CYLINDER

Flanged cylinders are round hydraulic cylinders with flanges. Thanks to their small dimensions they are often used in fixture and mold construction. The pressure ports are located in the screw-on flange, and thus at one end of the cylinder. In practice, flanged cylinders are best suited for strokes up to 100 mm; in addition, the use of double-lined cylinders is advisable.

 

 


CUBE CYLINDER (WKHZ)

Cube cylinders are cylinders with especially small external dimensions. They are thus used most often when there is not enough space for standard or block cylinders. Their maximum operating pressure is 400 bar (5800 PSI).

 

 


SHORT-STROKE CYLINDER (KHZ)

Short-stroke cylinders have an external thread over their entire length. This means that they can be screwed into or flanged directly to a fixture, and can thus be adjusted optimally. Such cylinders can be fixed very easily using the supplied lock nut. Both hydraulic connections are arranged axially on the cylinder bottom.

 

 


DOUBLE-LINED CYLINDER (DFZ)

Double lined cylinders are hydraulic cylinders with a very special design. Structurally they are designed with two cylinder tubes that are built one inside the other and sealed pressure-tight relative to each other. They can be ordered even for long strokes. The distinguishing feature of double lined cylinders is their round construction with a flange at one end. The flange is located either at the rod end or at the piston end. Attached to this flange are both ports for the forwards and return stroke, and the cylinder is also mounted on it. The use of double lined cylinders is always advisable when due to long strokes and installation in large molds one end of the cylinder is hard to access, and thus both ports have to be located on one end.

 

 


STANDARD CYLINDER (UZ, HZ, HZH)

AHP Merkle classifies its standard cylinders into three pressure ranges (100, 160 und 250 bar / 1450, 2320 and 3625 PSI) and four series (UZ 100, HZ 160, HZ 250 and HZH 250). These are all characterized by their round construction with a screwed head and bottom. Customers can choose between twelve different mounting options and the choice of integrated proximity switches or linear position transducer.

 

 


DIN STANDARD CYLINDER (DHZ, ZHZ)

DIN standard cylinders are designed and manufactured according to the installation dimensions as per the standards DIN ISO 6020/2 / DIN ISO 6020/1 / ISO 6022, DIN 24333. A distinction is made between the  pressure ranges 160 and 250 bar (2320 and 3625 PSI). Various mounting options are available.

 

 


PUSH UNITS (BSE, ZSE)

Thanks to their additional external guides, push units can absorb high transverse forces and torques. This series contains options with 2, 3 or 4 guide columns. A front plate can be used to mount customer-specific tools.

 

 

 


BLOCK PUSHER (BZS)

Block pusher units are modified block cylinders with integrated guides. This means that they are able to absorb certain side forces. Although these forces are smaller than with push units, on the other hand block pushers are very compact, and can be installed even in cramped spaces. This cylinder option provides an ideal combination of the advantages of block cylinders and push units.

 

 


LOCKING CYLINDER (VBZ)

Depending on the part geometry to be injected, it may be necessary to create a breakthrough or an undercut. The application requires keeping a core or a feeder in the cavity. This task is achieved through a Locking Cylinder. With its compact design, it withstands very high forces thanks to a mechanical locking mechanism (positive locking). This is mainly used in injection mold manufacturing.

 

 

 


STAMPING CYLINDER (STZ)

The stamping cylinders are a further development of the block cylinder. A characteristic feature of stamping cylinders is that thanks to the special design and arrangement of their seals and guides they can absorb the  large dynamic loads that are generated during stamping.

 

 


SCREW-IN CYLINDER (EZ)

The most space-saving option among AHP Merkle hydraulic cylinders are the screw in cylinders. Because these cylinders are screwed directly into the tool, the tool functions as a housing. The customer / user only has to   create the mounting bore with the associated intake bores for forwards and return travel in the tool. There are both single-acting and double-acting options.

 

 


CORE PULL UNITS (KZE)

Core pull units are primarily used in mold construction, but can also be used for other applications in which precise guiding is needed. By using these units, the user does not need to design an elaborate guide, such as those required with core pullers. The core pull unit is designed so that the entire piston surface is acted upon for „pulling“. Unlike with a pulling cylinder, this means that a smaller piston can be used with the same operating pressure. The space savings with this design can be up to 35% compared to conventional solutions. The precise guiding of the slide is ensured through the use of cross roller guides.

 

 


HYDRAULIC CYLINDER WITH EXTERNAL GUIDE (HZF)

These hydraulic cylinders are available with external guides for max. pressures of up to 160 bar (2320 PSI). The cylinder liner is plasma nitrated and suitable for use as a guide. These cylinders are used very often in aluminum die casting systems.

 

 

 


ROTARY DRIVE UNITS (DA)

There exist hydraulic rotary drives with angles of rotation from 0° to 720° and torques of up to 1,400 Nm (1,032 .59 foot-pound force). Here the rotational motion is achieved via a hydraulically driven rack-and-pinion system. Thus this type of kinematic system is not comparable to those with hydraulic motors.

The maximum torque is reached at the operating pressure of 50 bar.