Extrusion machine

1. An extrusion machine comprising:

a head body;

a die seat arranged on a front surface of the head body;

a die attached in a removable manner to the die seat, wherein the die includes an extrusion outlet that is in communication with an opening through which plastic material is discharged out of the head body;

a holding member that is in contact with a front surface of the die; and

a pressing mechanism that presses the holding member against the front surface of the die, wherein the pressing mechanism includes:

a bolt that presses the die against the die seat;

a first member coupled to the holding member;

a second member to which force is applied in one direction when the pressing produces a reaction force acting on the bolt; and

a cam surface arranged between the first member and the second member, wherein the cam surface causes the force applied in the one direction to the second member to act on the holding member toward the die.

2. The extrusion machine according to claim 1 , wherein the first member includes a first shaft inserted into a first bore of the die seat and provided with a head that is in contact with the holding member,

the second member includes:

a set member arranged on the die seat; and

a second shaft including a head that is in contact with the set member, wherein the second shaft is inserted into a second bore of the set member and the die seat, and

at least one of the first shaft and the second shaft includes a cam surface that is in contact with the other one of the first shaft and the second shaft.

3. The extrusion machine according to claim 1 , wherein the die is formed by two stacked die pieces, an extrusion outlet is formed between the die pieces, and the bolt presses the die pieces against each other.

4. The extrusion machine according to claim 2 , wherein the head body includes a spring that biases the first shaft in a direction in which the head of the first shaft moves away from the holding member.