H 06 X VH NPK H 06 X VH Specifications & Technical Data (1996—2001)

Preload the tool before starting

Press the tip of the demolition tool vertically against the object to be broken. Be sure the object is stable before activating the NPK HYDRAULIC HAMMER. Raise the front of the machine slightly by applying downforce on the demolition tool. Press the control lever or the foot pedal to start the NPK HYDRAULIC HAMMER. Applying excessive force to the hammer will raise the carrier too high and jolt the operator when the material breaks. Let the NPK HYDRAULIC HAMMER do the work.

Avoid blank hammering

As soon as the material is broken, release the control lever or pedal to prevent unnecessary blank hammering. Blank hammering is continued hammer operation after the material is broken. This will overheat the hydraulic system and cause undue wear.

Do not slant hammer

For the most efficient demolition, align the direction of force (F) from the boom with the penetration direction (P) of the tool. Failure to do this decreases the transfer of energy from the piston to the rock and increases the bending forces at the fulcrum of the tool. This unnecessary added stress leads to the following problems: Premature bushing wear and/or tool breakage Breakage of tie rods Breakage of bracket bolts. When the tool binds from incorrect working angle, the sound of the hammer changes. Keep the boom direction of force in the same direction the tool is penetrating. Use the boom cylinder to preload the hammer (apply downforce), and use the bucket and stick cylinders for alignment. Keep the tool tangent to the arc of the boom.

Do not use the demolition tool as a pry bar

Excessive prying can cause premature bushing wear and tool or tie rod breakage. When hammering materials that allow the tool to penetrate before breaking, move the hammer slightly fore and aft to create a cone-shaped hole. The vented hole allows trapped dust and heat to escape, increases the tool penetration rate into the material, and prevents overheating the tool tip.

Do not hammer continuously in the same position for more than 30 seconds

If the tool cannot break or penetrate into the material after hammering in the same position for 30 seconds, change the working location. Hammering in the same position for a long time will reduce the working efficiency, increase the hydraulic oil temperature, and accelerate tool wear.

Beware of flying projectiles from the hammer point

Do not use the hammer in such a way as to cause rock, etc. to be thrown towards the cab.

Do not operate the hammer without the cab window or shield in place

Cab window or shield must be in place to protect the operator from rock thrown out from the tool point.

Correct Grease and Grease Intervals

Proper hammer maintenance requires a sufficient supply of the correct grease to the tool (chisel). The tool must be pressed against a hard surface until it stops up inside the hammer. This prevents grease from entering piston impact area and ensures proper distribution of grease between the tool and tool bushings.

Storage of Hydraulic Hammer

For short term storage between jobs, place the hammer horizontal on wood blocks. Be sure the tool is liberally greased and the hydraulic hoses are capped. Cover with a waterproof tarp. If the NPK HYDRAULIC HAMMER is not to be used for a long period of time (months), it is recommended the gas pressure be discharged. The tool should be removed, and the piston pushed all the way in. Be sure the hydraulic hoses are plugged and grease the exposed end of the piston. Grease and reinstall the tool. Cover with a waterproof tarp.

Hammer Kit Lines

Typically, the pressure line is arranged on the left side of the boom and the return line on the right side. Flow to the hammer is controlled from an auxiliary valve on the excavator or from an NPK supplied valve. Hydraulic oil is routed back to the tank through the excavator’s oil cooler and filter.

Hammer Control Valve

NPK uses two general types of control systems, depending upon the carrier model:Control System Using the Carrier Auxiliary or Spare Valve Section. This type of installation utilizes an existing carrier valve. Any additional parts, such as a mechanical linkage, hydraulic pilot actuators, flow control valves, etc., are furnished in the NPK HYDRAULIC INSTALLATION KIT. Special hydraulic pressure control valves are not required. The NPK HYDRAULIC HAMMER operating pressure is self-regulating.Control System Using the NPK Multivalve. For carriers not equipped with a suitable auxiliary or spare valve section, the NPK HYDRAULIC INSTALLATION KIT includes a solenoid operated, priority flow control valve to operate the NPK HYDRAULIC HAMMER. The NPK MULTIVALVE is specifically designed for the operation of boom mounted attachments.

Prevention of Contamination in the Hydraulic System

A hydraulic hammer is harder on oil than using a bucket, so the oil is apt to deteriorate and become contaminated sooner. Neglect of the oil system can not only damage the hydraulic hammer but also cause problems in the excavator which could result in damaged components. Care should be taken to check for contamination of the oil and to change it if it is found contaminated. When the hydraulic oil shows low viscosity and bubbles, this indicates that the oil is deteriorated. If the oil is dark brown and gives off an offensive odor, it is severely deteriorated. Change the oil immediately. When the oil is clouded, or the oil filter often becomes clogged, it indicates that the oil is contaminated. Change the oil. To change the contaminated hydraulic oil, drain the hydraulic system completely and clean components. Do not mix new oil with the old.

Contamination Prevention

Do not allow any contamination to mix with the oil. Take special care in preventing contamination from entering the hydraulic system through the hose or tube connection when changing the hydraulic hammer with the bucket.

Oil Level and Temperature

Low oil level will cause heat build-up, resulting in deterioration of the oil. Also, it may cause cavitation due to air mixing with the oil, leading to a damaged hydraulic hammer and carrier components. Keep the oil at the proper level at all times. Additionally, do not use the hydraulic hammer at an operating temperature higher than 180°F (80°C). The proper operating oil temperature range is between 120°F (50°C) and 180°F (80°C). Since contaminated cooler fins cause reduced efficiency of the cooler, keep the cooler fins clean at all times.

Water in Hydraulic Oil

Water in the hydraulic oil will lead to damage of the hydraulic hammer. When out of service, the hydraulic hammer should be stored indoors. Drain off water and foreign matter from the hydraulic tank at specified intervals.

Changing the Filter Element and Hydraulic Oil

Change the filter element and hydraulic oil at the intervals described in the operation manual of the excavator when using a hydraulic implement. Another method is to set up an oil sampling schedule and change accordingly.

Important

The hydraulic lines must be handled carefully and sealed to prevent contamination from entering the hammer or the carrier hydraulic system.

Quick Disconnects and Contamination

The hydraulic pulsations caused by the hammer operating can cause internal pieces of non-NPK quick disconnect to disintegrate. These pieces would migrate into the hammer, causing damage. If quick disconnects are used when the hammer is removed from the excavator, the quick disconnects should be capped to keep them clean. If this is not done, contamination on the disconnect will be flushed into the hammer when reconnected. This, again, can cause damage. Most quick disconnects create a restriction in the circuit. NPK hammers are not back pressure sensitive, but restrictions cause unnecessary heating of the oil. Additionally, the pressure required to operate the hammer, plus the restriction of the disconnects may push an older, low pressure excavator to the limit of its hydraulic system, interfering with proper hammer operation. However, the NPK approved quick disconnects are properly sized so that the hammer operation is not affected.

Nitrogen gas pressure

The nitrogen gas pressure must be measured with no preload on the tool. Remove the tool; or position the hammer with the tool fully extended against the tool retaining pin. The hammer must not be resting vertical on the tool. The gas pressure in the hammer will vary according to the gas temperature.

Preferred method

The preferred method to measure or charge the nitrogen gas pressure is with the hydraulic system temperature stabilized at maximum operating temperature.

Alternate method

The nitrogen gas pressure can be measured or charged at ambient temperature (cold), before operating the hammer. It is recommended the pressure be verified at operating temperature.

Gas charging kit

ALL NPK HYDRAULIC HAMMERS are furnished with the following gas charging kit. In addition, a nitrogen tank and pressure regulator valve (not furnished with the hammer) are required. These can be obtained from your local welding supply house. A regulator valve is available from NPK.

Gas Charging Procedure

Install a pressure regulator on a tank of nitrogen gas. Connect a hose from the pressure regulator on the nitrogen tank to the charge adapter. Turn the T-handle on the charge adapter clockwise. Turn the handle on the tank regulator counterclockwise to full closed. Open the valve on the nitrogen tank by turning the handle counterclockwise. Slowly adjust the regulator on the nitrogen tank to the correct pressure by turning clockwise. See NITROGEN GAS PRESSURE, page 36. Charge nitrogen gas until the pressure gauge on the charge adapter is at the correct setting, then turn the T-handle counterclockwise all the way out. Close the nitrogen tank valve and then remove the hose from the charge adapter. Remove the charge adapter from the hammer charge valve. Replace the charge valve cap.

Discharging the Gas Pressure

Remove the charge valve cap. Turn the NPK charging adapter T-handle counterclockwise until it stops. Install the NPK charging adapter on the hammer charge valve. Tighten the charging adapter cap. Turn the T-handle clockwise. As the T-handle is screwed in, a resistance is encountered. By turning the T-handle further, the nitrogen gas pressure will be indicated on the pressure gauge. Stop turning the T-handle when the gauge reads pressure. Do not over tighten. Loosen the charge adapter cap VERY SLOWLY. The gas pressure will gradually decrease to zero; then REMOVE THE CAP. Remove the charge adapter from the hammer and reinstall charge valve cap.

Changing the tool

If the HAMMER is mounted on the carrier machine, close the shut-off valves on the end of stick. With the accessory bar and a hammer, remove the spring pin. Remove the retaining pin. Remove the tool. Tool may be HOT! Prior to installation, apply a liberal coating of moly base, high temperature grease on the sliding surfaces of the tool and retaining pin. Install the tool. Insert the retaining pin. Install the cushioned washer over the retaining pin. The rubber must be against the tool holder. Drive in the spring pins as shown below. Open the shut-off valves on the end of stick. Remove the retaining ring by using pliers. It will easily come out if pulled at an angle of 30° with the center as shown in figure below. Screw an M12 bolt or cap screw into the retainer pin. Pull out retainer pin. If the retainer pin holds so tight it cannot be pulled out, hammer it out from the opposite side. Clean the retainer pin housing hole and retaining ring holding groove. Coat the surface of the chisel with heat resistant grease, then install the chisel. Apply grease to the retaining ring housing groove. Coat the retainer pin with heat resistant grease, then install it. Install the retaining ring in the following procedure. While deforming the retaining ring as shown in figure below, partially force it into the groove. Using the handle of the pliers, press the rest of the ring into the groove little by little.