Spindle supporting box structure, a damping structure, a gas supply related device, and a balance cylinder gas actuated device for machine tools

A spindle supporting box structure for machine tools:

• wherein a slit is provided at each of longitudinal side faces facing in a front-back direction;
• wherein a spindle is installed across the slits to move up and down;
• wherein each of right and left longitudinal side faces facing in a direction approximately perpendicular to the above longitudinal side faces, with the spindle therebetween, is formed by tubular members having suitable flexural rigidity;
• wherein a longitudinal tubular member at the longitudinal side faces has a geometric cross section;
• and
• wherein the typical size of the cross section is about 1/7 to 1/4 of the front-back or right-left length of the spindle supporting box structure.

A damping structure for machine tools:

• wherein a required framework of a structure is formed by tubular members;
• wherein concrete is filled in the tubular members, and then solidified;
• and
• wherein the concrete is airtightly sealed in the tubular members.

A gas supply related device for machine tools:

• wherein a framework functioning as a reinforcing member of a structure is formed by tubular members;
• wherein an inner space of the tubular members is made into a gas pressure space;
• wherein a gas pressurized tank is connected with a gas actuated device by means of a gas passage means;
• wherein the gas actuated device is a balance cylinder;
• wherein the gas pressure means is a gas passage tube for passing gas;
• and
• wherein a balance pressurized control valve is provided in the middle of the gas passage tube.

A balance cylinder gas actuated device for a machine tool having a framework formed by tubular members comprising:

• a gas pressurized tank;
• a balance cylinder defining a cylinder chamber;
• and
• a gas passage connecting said gas pressurized tank with said balance cylinder chamber such that gas in the gas pressurized tank directly acts on the cylinder chamber,
• wherein one of the tubular members defines the gas pressurized tank.

A spindle supporting box structure for machine tools comprising:

• a box having first opposed faces facing in a front-back direction and second opposed faces facing substantially perpendicular to said first opposed faces;
• a slit defined in each of said first opposed faces;
• and
• a spindle device mounted on said box for up and down movement, said spindle device extending through each of said slits,
• wherein each of said second opposed faces has sides defined by first flexurally rigid tubular members.