Temperature control in machine tools

A fluid temperature control apparatus in combination with a machine tool, wherein the apparatus is arranged to adjust a temperature of a fluid being supplied to the machine tool to maintain the fluid at a setpoint temperature at a first location which is downstream of the apparatus, and the apparatus comprises:

• a temperature control assembly for adjusting the temperature of the fluid as it passes through the assembly, the assembly having a fluid inlet for receiving a flow of the fluid and a fluid outlet for outputting the fluid;
• a fluid conduit arrangement which is coupled to the fluid outlet to carry the fluid to the machine tool;
• a first temperature sensor for outputting a first temperature signal responsive to the temperature of the fluid at the first location;
• a controller configured to receive the first temperature signal and control the temperature control assembly with reference to the first temperature signal so as to maintain the fluid at the setpoint temperature at the first location;
• a fluid return path for carrying fluid from the machine tool to the fluid inlet;
• a heat exchanger in the fluid return path for transferring heat energy to or from fluid flowing along the fluid return path;
• and
• wherein the temperature control assembly comprises at least one thermoelectric temperature control device and a thermal exchanger, and the thermal exchanger forms part of a fluid path between the fluid inlet and the fluid outlet and is thermally coupled to the at least one thermoelectric temperature control device, wherein the temperature control assembly includes a temperature regulator for removing heat from the at least one thermoelectric temperature control device, wherein the at least one thermoelectric temperature control device is thermally coupled between the thermal exchanger and the temperature regulator, wherein the temperature regulator is fluidically coupled to a coolant fluid path for carrying coolant fluid to and from the temperature regulator, and wherein the coolant fluid path includes a valve for selectively diverting a proportion of the coolant fluid flowing along the coolant fluid path to the heat exchanger to receive heat energy drawn from fluid flowing along the fluid return path;
• and
• wherein the apparatus further comprises a valve controller for adjusting the valve, wherein the valve controller is configured to receive a valve control signal responsive to an operating parameter of the machine tool, and to adjust the valve with reference to the valve control signal.